- Cu2S-EuS phase diagram1
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In the Cu2S-EuS system, a eutectic is formed between Cu2S- and EuS-based solid solutions (ss) at (1069 ± 2) K, 24.5 mol % EuS. EuS dissolves 7.0 (at 1770 K), 5.0 (1170 K), and 3.0 (770 K) mol % Cu2S. A β-Cu2S-based ss is of the open type, has an extent (mol %) of 15.5 (at 1069 K), 7.5 (970 K), 4.5 (770 K), 2.5 (520 K), and 1.5 (379 K) EuS, and melts incongruently at 1186 K, 7.0 mol % EuS. α-Cu2S at 379 K dis- solves 6.5 mol % EuS; γ-Cu2S at (1186 ± 3) K dissolves 3.5 mol % EuS. Pleiades Publishing, Ltd., 2012.
- Andreev,Ruseikina
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- Size-controlled synthesis of quantum-sized EuS nanoparticles and tuning of their Faraday rotation peak
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Size-controlled EuS nanoparticles were synthesized by the reaction of europium metal with thiourea as a sulfur source in liq. NH3, whose surface was confirmed to be modified with thiourea by FT-IR measurement, and the opto-magnetic properties (Faraday effect) of the EuS nanoparticles were investigated by using PMMA films containing the nanoparticles, showing that their Faraday rotation peaks were adjustable by control of their particle size. The Royal Society of Chemistry 2005.
- Kataoka, Tomoharu,Tsukahara, Yasunori,Hasegawa, Yasuchika,Wada, Yuji
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- Heterometallic Eu/M(II) Benzenethiolates (M = Zn, Cd, Hg): Synthesis, Structure, and Thermolysis Chemistry
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Europium-mercury amalgam reacts with diphenyl disulfide in THF to give a heterometallic product that crystallizes from pyridine (py) as [(py)3Eu(μ2-SPh)2(μ3-SPh)Hg(SPh)]2.2py (1). Cluster 1 reacts with Cd in pyridine to give [(py)3Eu(μ2-SPh)2(μ3-SPh)Cd(SPh)]2.2py (2) and with Zn in THF to give [(THF)3Eu(μ2-SPh)2(μ3-SPh)Zn(SPh)]2.THF (3). All three compounds have been characterized by NMR, IR, and UV-visible spectroscopy and by single-crystal X-ray diffraction. The three are structurally related; 1 and 2 are isostructural tetrametallic clusters with μ2 and μ3 thiolate ligands connecting the 7-coordinate Eu(II) and tetrahedral group 12 metal ions. The lanthanide coordination sphere is saturated with three neutral pyridine donors, and the group 12 metal ion isbound to a terminal benzenethiolate ligand. The zinc cluster 3 has the same tetrametallic framework and connectivity as 1 and 2 but crystallizes in a different unit cell. The thermolysis products of these compounds have been established: 1 decomposes to give EuS, Ph2S, Hg, and S2Ph2; 2 eliminates Ph2S to give a mixture of CdS and EuS; 3 eliminates Ph2S to give a mixture of EuS and ZnS. Crystal data for 1-3 (Mo Kα radiation, -100°C): 1, triclinic space group P1-, a = 13.954(3) ?, b = 15.311(4) ?, c = 19.666(8) ?, α = 84.54(3)°, β = 86.40(3)°, γ = 87.25(3)°, Z= 2; 2, triclinic space group P1-, a = 13.968(3) ?, b = 15.387(6) ?, c = 19.993(8) ?, α = 84.74(3)°, β = 86.21(3)°, γ = 87.30(3)°, Z = 2; 3, monoclinic space group P21/n, a = 13.920(5) ?, b = 17.049(5) ?, c = 17.823(6) ?, β = 103.7(3)°, Z = 4.
- Brewer, Meggan,Lee, Jongseong,Brennan, J. G.
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- Sulfurization of rare-earth oxides with CS2
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In the scheme of spent fuel reprocessing by using sulfides, selective sulfurization of rare-earths in the fuel is considered followed by either magnetic separation or selective leaching of rare-earth sulfides from uranium oxides such as UO2. In this paper, sulfurization behavior of rare-earth oxides was investigated by XRD and TG methods in the presence of CS2. From the results of thermogravimetric study the sulfurization of europium proceeds as follows; sulfurization from Eu2O3 to Eu3S4 occurs at ca. 400 °C, then the Eu3S4 decomposes to EuS via non-stoichiometric sulfides at temperatures between 450 and 700 °C. From the results of thermogravimetry for Nd2O3, it was found that the weight curve showed monotonic increase from ca. 600 to 1000 °C. At 1000 °C, the value of weight increase was close to that for the formation of Nd2S3 from Nd2O3. The XRD result of the 1000 °C product showed a formation of a single phase of Nd2S3 which is compared with the thermogravimetric result as well as our previous results. The selective sulfurization of rare-earths in the mixture of rare-earth and uranium oxides was discussed by both experimental results and thermodynamical consideration.
- Sato, Nobuaki,Shinohara, Genki,Kirishima, Akira,Tochiyama, Osamu
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- Synthesis, structure and physicochemical characterization of a noncentrosymmetric, quaternary thiostannate: EuCu2SnS4
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EuCu2SnS4 was prepared by a stoichiometric combination of the elements heated to 700 °C for 125 h. The structure was determined by single crystal X-ray diffraction methods. The compound crystallizes in the noncentrosymmetric, orthorh
- Aitken, Jennifer A.,Lekse, Jonathan W.,Yao, Jin-Lei,Quinones, Rosalynn
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- A novel method for synthesizing EuS nanocrystals from a single-source precursor under white LED irradiation
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EuS nanocrystals, with an average diameter of 9 nm, have been synthesized by the photolysis of Na[Eu(S2CEt2)4]·3. 5H2O; the first quantum confined particles of EuS to be reported.
- Hasegawa, Yasuchika,Afzaal, Mohammad,O'Brien, Paul,Wada, Yuji,Yanagida, Shozo
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- Regularities of the property changes in the compounds EuLnCuS3 (Ln = La-Lu)
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This work contains the results of complex experimental research of the compounds EuLnCuS3 (Ln = La-Lu) enhanced by the DFT calculations. It is aimed at the data replenishment with particular attention to the revelation of regularities in the property changes, in order to extend the potential applicability of the materials of the selected chemical class. The ab initio calculations of the fundamental vibrational modes of the crystal structures were in good agreement with experimental results. The wavenumbers and types of the modes were determined, and the degree of the ion participation in the modes was also estimated. The elastic properties of the compounds were calculated. The compounds were found out to be IR-transparent in the range of 4000–400 cm–1. The estimated microhardness of the compounds is in the range of 2.68–3.60 GPa. According to the DSC data, the reversible polymorphous transitions were manifested in the compounds EuLnCuS3 (Ln = Sm, Gd-Lu): for EuSmCuS3 Tα?β = 1437 K, ΔНα?β = 7.0 kJ·mol-1, Tβ?γ = 1453 K, ΔНβ?γ = 2.6 kJ·mol-1; for EuTbCuS3 Tα?β = 1478 K, ΔНα?β = 1.6 kJ·mol-1, Tβ?γ = 1516 K, ΔНβ?γ = 0.9 kJ·mol-1, Tγ?δ = 1548 K, ΔНγ?δ = 1.6 kJ·mol-1; for EuTmCuS3 Tα?β = 1543 K, Tβ?γ = 1593 K, Tγ?δ = 1620 K; for EuYbCuS3 Tα?β = 1513 K, Tβ?γ = 1564 K, Tγ?δ = 1594 K; for EuLuCuS3 Tα?β = 1549 K, Tβ?γ = 1601 K, Tγ?δ = 1628 K. In the EuLnCuS3 series, the transition into either ferro- or ferrimagnetic states occurred in the narrow temperature range from 2 to 5 K. The tetrad effect in the changes of incongruent melting temperature and microhardness conditioned on rLn3+ as well as influencing of phenomenon of crystallochemical contraction were observed. For delimiting between space groups Cmcm and Pnma in the compounds ALnCuS3, the use of the tolerance factor t’ = IR(A)·IR(C) + a×IR(B)2 was verified.
- Ruseikina, Anna V.,Chernyshev, Vladimir A.,Velikanov, Dmitriy A.,Aleksandrovsky, Aleksandr S.,Shestakov, Nikolay P.,Molokeev, Maxim S.,Grigoriev, Maxim V.,Andreev, Oleg V.,Garmonov, Alexander A.,Matigorov, Alexey V.,Melnikova, Ludmila V.,Kislitsyn, Anatoliy A.,Volkova, Svetlana S.
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- Anomalous Eu valence state and superconductivity in undoped Eu3Bi2S4F4
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We have synthesized a novel europium bismuth sulfofluoride, Eu3Bi2S4F4, by solid-state reactions in sealed evacuated quartz ampules. The compound crystallizes in a tetragonal lattice (space group I4/mmm, a = 4.0
- Zhai, Hui-Fei,Zhang, Pan,Wu, Si-Qi,He, Chao-Yang,Tang, Zhang-Tu,Jiang, Hao,Sun, Yun-Lei,Bao, Jin-Ke,Nowik, Israel,Felner, Israel,Zeng, Yue-Wu,Li, Yu-Ke,Xu, Xiao-Feng,Tao, Qian,Xu, Zhu-An,Cao, Guang-Han
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- Crystal structure of EuCeCuS3
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The crystal structure of EuCeCuS3, a complex sulfide synthesized for the first time, has been solved using X-ray powder diffraction data. Crystals are rhombic, space group Pnma, Ba2MnS3 structural type, a = 8.1023(1) ?, b = 4.0386(1) ?, c = 15.9022(2) ?, V = 520.36(1) ?3, Z = 4, ρcalcd = 5.767 g/cm3. The Eu,CeS7 polyhedron incorporates the Eu and Ce atoms, which are randomly disordered over two crystallographic sites. The bond lengths dEu,Ce–S range from 2.885 to 3.044 ?.
- Ruseikina
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- UV-VIS-NIR luminescence properties of an intense 5d broadband sensitized Eu2SiS4:Er3+ suitable for solar spectral converter
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A novel broadband sensitized near-infrared emitting phosphor, Eu2SiS4:Er3+, was developed as promising solar spectral converter for Si solar cells. Eu2SiS4:Er3+ has broadband absorptions ranging from 250 nm to 550 nm which can efficiently facilitate the UV-green part of the solar photon flux spectrum and exhibits intense NIR emission of Er3+, perfectly matching the maximum spectral response of Si solar cells. The NIR integrated emission intensity of Eu2SiS4:0.02Er3+ is 6.14 times as intense as that of a dual-mode solar spectral converter CaLaGa3S6O:0.01Ce3+, 0.06Pr3+. These results demonstrate that Eu2SiS4:Er3+ phosphor is a promising candidate used as solar spectral converter.
- Zhang, Gongguo,Cui, Qiuyu,Liu, Guodong
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- Physical and optical properties of the quaternary sulfides SrCu2MS4 and EuCu2MS4 (M=Ge and Sn)
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Four quaternary sulfides SrCu2MS4 and EuCu2MS4 (M=Ge and Sn) were prepared from a thoroughly ground mixture of EuS or SrS, Cu, or Sn, and S in stoichiometric proportions. Electrical conductivity measurements on pressed pellets showed that all the phases are semiconductors. The optical band gaps were assessed at 2.8eV for SrCu2GeS4, 2.1eV for SrCu2SnS4, 2.2eV for EuCu2SnS4, and 1.6eV for EuCu2GeS4. Both Sr-based compounds present a temperature-independent paramagnetism, of about +135×10-6 and +92×10-6emu/mol, for SrCu2SnS4 and SrCu2GeS4, respectively. In the case of the europium compounds, they follow a Curie-Weiss dependence above 1.8K (EuCu2GeS4) and above 4K (for EuCu2SnS4), with values of the magnetic effective moment μeff and the Curie-Weiss temperature Θ, equal to 6.27μB and -2.8K for EuCu2GeS4, and 6.81μB and +0.7K, for EuCu2SnS4. The experimental magnetic moments confirm that the europium ion is in divalent state, similar to Sr in the related compounds.
- Llanos, Jaime,Mujica, Carlos,Sanchez, Victor,Pena, Octavio
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- Eu2+-doped thioaluminates: New candidates for white LEDs
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Three Eu2+-doped thioaluminate phosphors with different light-emitting colors, green, bluish-green, and blue were synthesized by the evacuated sealed quartz ampoule method. Under UV excitation, CaAl 2S4:Eu2+ (CA
- Yu, Ruijin,Wang, Jing,Zhang, Xinmin,Yuan, Haibin,Zhang, Jianhui,Su, Qiang
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- Synthesis, structure, and properties of EuErCuS3
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The crystal structure of the first-synthesized compound EuErCuS3 was determined from X-ray powder diffraction data: orthorhombic crystal system, space group Pnma, structural type Eu2CuS3: a = 10.1005(2) ?, b = 3.91255(4)?, c = 12.8480(2) ?; V = 507.737(14) ?3, Z = 4, and ρx = 6.266 g/cm3. The temperatures and enthalpies of reversible polymorphic transitions and incongruent melting of the compound were determined by DSC: Tα?β = 1524 K, ΔНα?β = 2.3 ± 0.2 kJ?mol?1; Tβ?γ = 1575 K, ΔНβ?γ = 0.7 ± 0.1 kJ?mol?1; Tγ?δ = 1602 K; ΔНγ?δ = 1.3 ± 0.1 kJ?mol?1 and Tcr = 1735 ± 10 K, ΔНcr = ?3.5 ± 0.3 kJ?mol?1. IR spectra were recorded in the range from 50 to 400 cm?1. The compound was found to be IR-transparent in the range 4000–400 cm?1. The compound was characterized by Raman spectroscopy. The observed spectra featured both Raman lines and luminescence. Ab initio calculations of the EuErCuS3 crystal structure and phonon spectrum were performed, the frequencies and types of fundamental modes were determined, and the involvement of constituent ions in the IR and Raman modes was assessed from an analysis of the ab initio displacement vectors. The vibrational spectra were interpreted. EuErCuS3 manifests a ferrimagnetic transition at 4.8 K. Its microhardness is 2850 MPa. The obtained data can serve as the basis for predicting the properties of EuLnCuS3 compounds. Valence states for Eu (2+) and Er (3+) are proved both by the XRD and optical methods. Optical band gap was found to be 1.934 eV from diffuse reflectance spectrum.
- Ruseikina, Anna V.,Solovyov, Leonid A.,Chernyshev, Vladimir А.,Aleksandrovsky, Aleksandr S.,Andreev, Oleg V.,Krylova, Svetlana N.,Krylov, Alexander S.,Velikanov, Dmitriy А.,Molokeev, Maxim S.,Maximov, Nikolai G.,Grigoriev, Maxim V.,Garmonov, Alexander A.,Matigorov, Alexey V.
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- Dye-coated europium monosulfide
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Nanoparticles of EuS were synthesized using europium dithiocarbamate complexes. The resulting nanoparticles were coated with the dye, 1-pyrene carboxylic acid and the resulting material was characterized using X-ray powder diffraction, TEM, and UV-visible spectroscopy. Fluorescence spectroscopy was used to determine the relative energy of the conduction band edge to the excited state energy of the dye.
- Kar, Srotoswini,Dollahon, Norman R.,Stoll, Sarah L.
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- New superconducting sulfide - `EuNb2S5'
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A new low-temperature superconducting (Tc≈3 K) niobium sulfide `EuNb2S5' with a hexagonal structure (a = 3.3556(8) angstroms, c = 23.440(9) angstroms) was synthesized from a mixture of EuS, Nb(m) and S in evacuated and sealed silica tubes, heated at 1100 °C for 48 h. This superconductor was characterized by EDX analysis, X-ray powder and electron diffraction studies. Electron diffraction revealed the presence of a supercell: asuper = bsuper = √7×a.
- Istomin,Grippa,D'yachenko,Antipov,Svensson,Tholence
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- Synthesis and properties of ZnS-EuS films grown from volatile complex compounds
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Deposition and characterization of films of ZnS, EuS and ZnS:Eu are described. The films have been prepared by chemical vapor deposition using new volatile complex compounds, dithiocarbamates of Zn and Eu, as precursors. Characterization includes X-ray diffraction, chemical analysis of the film composition, Raman spectroscopy, ellipsometry, and spectrophotometry. The spatial chemical homogeneity of the films has been determined using a recently developed method of differential dissolution and found to be uniform. Doping of ZnS by Eu with dopant concentration up to 0.3 at.% has been achieved. Effects of Eu doping on structural and optical properties of the films are presented.
- Bessergenev,Ivanova,Kovalevskaya,Vasilieva,Varand,Zemskova,Larionov,Kolesov,Ayupov,Logvinenko
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- Magnetization reversal in europium sulfide nanocrystals
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The authors report the observation of the reversal in the magnetization hysteresis curve of europium sulfide nanocrystals. This phenomenon was investigated through the temperature-dependent magnetization of two classes of nanomaterials, nanocrystalline (2
- Redigolo, Marcela L.,Koktysh, Dmitry S.,Rosenthal, Sandra J.,Dickerson, James H.,Gai, Zheng,Gao, Lan,Shen, Jian
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- Phase diagrams of sections in the EuS-Cu2S-Nd2S 3 system
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Phase equilibria in the EuS-Cu2S-Nd2S3 system were studied in an isothermal (970 K) section and NdCuS2-EuS and Cu2S-EuNdCuS3 polythermal sections. The complex sulfide EuNdCuS3 has an orthorhombic crystal lattice (space group Pnma; a = 1.10438(2) nm, b = 0.40660(1) nm, c = 1.14149(4) nm), is isostructural to BaLaCuS3, and melts incongruently at 1470 K: EuNdCuS3 (0.50 EuS; 0.50 NdCuS2) ai 0.18 EuS ss (0.88 EuS; 0.12 NdCuS 2) + 0.82 L (0.415 EuS; 0.585 NdCuS2); ΔH = 17.8 kJ/mol. Within the range 0.5 mol % EuS, EuNdCuS3-based solid solutions were not found. At 970 K, the tie lines pass from the compound EuNdCuS3 to Cu2S, EuS, NdCuS2, and EuNd 2S4 phases and lie between the NdCuS2 phase and solid solutions (ss) of γ-Nd2S3 with EuNd 2S4. Eutectics are formed between the compounds NdCuS 2 and EuNdCuS3 at 32.0 mol % EuS T = 1318 K and between the compounds Cu2S and EuNdCuS3 at 20.5 mol % EuNdCuS 3 and T = 1142 K. Five main subordinate triangles were identified in the system.
- Andreev,Ruseikina,Solov'Ev
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- Luminescence properties of Eu2+- and Ce3+-doped CaAl2S4 and application in white LEDs
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The Eu2+- and Ce3+-doped CaAl2S4 phosphors were comparatively synthesized by conventional solid-state reaction and the evacuated sealed quartz ampoule. The X-ray diffraction (XRD) patterns show that the sample with better crystalline quality was prepared by the evacuated sealed quartz ampoule, resulting in the enhancement of the emission intensity of Eu2+ ion by a factor of 1.7. The intensive green LEDs were also fabricated by combining CaAl2S4:Eu2+ with near-ultraviolet InGaN chips (λem=395 nm). The dependence of as-fabricated green LEDs on forward-bias currents shows that it presents good chromaticity stability and luminance saturation, indicating that CaAl2S4:Eu2+ is a promising green-emitting phosphor for a near-UV InGaN-based LED. In addition, the optical properties of CaAl2S4:Ce3+ were systematically investigated by means of diffuse reflectance, photoluminescence excitation and emission, concentrating quenching and the decay curve.
- Yu, Ruijin,Wang, Jing,Zhang, Jianhui,Yuan, Haibin,Su, Qiang
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- Luminescence properties of Ca1-xSrx(Ga 1-yAly)2S4: Eu2+ and their potential application for white LEDs
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A series of Ca1-xSrx(Ga1-yAl y)2S4:0.10 Eu2+ (0.0≤x≤1.0, y=1.0; 0.0≤y≤1.0, x=0) phosphors was synthesized by the evacuated sealed quartz ampoule method. X-ray powder diffraction analysis confirmed the formation of the complete solid solutions of Ca1-xSrx(Ga 1-yAly)2S4:0.10 Eu2+ and Ca(Ga1-yAly)2S4:0.10 Eu 2+. With the Sr(x) and Al(y) content increasing, the emission peaks of Ca1-xSrxAl2S4: Eu2+ and Ca(Ga1-yAly)2S4: Eu2+ show an obvious blueshift in the range of 496-556 nm. A tunable bluish-green to greenish-yellow light can be controlled by simply adjusting the content of Sr(x) in Ca1-xSrxAl2S4: Eu 2+ and Al(y) in Ca(Ga1-yAly)2S 4: Eu2+. All the characteristics indicate that the Ca 1-xSrx(Ga1-yAly)2S 4: Eu2+ solid solution phosphors are good phosphor candidates for white light-emitting diodes (LEDs).
- Yu, Ruijin,Wang, Jing,Zhang, Mei,Yuan, Haibin,Ding, Weijia,An, Yun,Su, Qiang
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- Magnetic properties of lanthanide chalcogenide semiconducting nanoparticles
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To understand the importance of the band gap to the magnetic ordering in magnetic semiconductors, we have studied the effect of particle size on the ferromagnetic Curie temperature in semiconducting EuS. We have synthesized capped ~20 nm EuS nanoparticles using a single-source precursor, [Eu(S 2CNBu2)3Phen] decomposed in trioctylphosphine. The nanoparticles have been characterized by X-ray powder diffraction, TEM, and magnetic susceptibility measurements as a function of temperature and field. The Curie temperature, based on Arrott plots, is depressed by 1-2 K from the bulk value.
- Regulacio, Michelle D.,Bussmann, Konrad,Lewis, Brad,Stoll, Sarah L.
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- Synthesis and crystal structure of two new oxychalcogenides: Eu5V3S6O7 and La10Se14O
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The crystal structure determination of two new oxychalcogenides, namely Eu5V3S6O7 and La10Se14O, is reported. Eu5V3S6O7 crystallizes in the orthorhombic symmetry (space group Pmmn) with unit cell parameters (in ?): a=17.463(2), b=3.6732(4), and c=10.007(1). This compound is isotypic with the Ln5V3S6O7 compounds (Ln=La-Nd), and its structure has been refined to R1=0.0248. Eu atoms, which are nine-coordinated by O and S atoms, are associated to form ribbons that are interconnected by [VS4O2] octahedrons. La10Se14O crystallizes in the tetragonal symmetry (space group I41/acd) with unit cell parameters (in ?): a=15.926(2), and c=21.061(5). The structure was refined to R1=0.0347. La10Se14O is isostructural with the Pr10X14O compounds (X=S and Se). The only structure difference is observed for one La site that is found split, in connection with a mixed O/Se site filling.
- Meerschaut,Lafond,Palvadeau,Deudon,Cario
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- Solvent assisted and solvent free orientation of growth of nanoscaled lanthanide sulfides: Tuning of morphology and manifestation of photocatalytic behavior
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A new class of precursor complexes Ln(acda)3(phen), (where Ln = Nd, Sm, Eu, Tb and Yb, acda- is the anion of 2-aminocyclopentene-1-dithiocarboxylic acid and phen stands for 1,10-phenanthroline) have been used to obtain phase pure lanthanide sulfide nanoparticles by solution-based as well as solution-free thermal treatments at inert conditions. During solution-phase thermolysis, long chain alkyl-amine solvents have been used to promote the reaction at much lower temperature (280 °C) than the solid-phase reaction (650 °C). A contrasting growth feature is observed for nano sulfides and consequently the shape of the material is varied from isotropic cube-like morphology to anisotropic short nanofibers according to the variation of surfactants. The study confirmed that the introduction of 1-dodecanethiol as a structure-modifying capping agent along with reacting amine significantly facilitates the anisotropic growth in a preferred direction. These have been characterized by XRD, TEM, FESEM, UV-vis spectroscopy and BET surface area measurements. The optical absorption data indicated a narrow band gap energy ranging from 1.71-1.97 eV for different EuS. The material emerged as a highly active visible light-driven photocatalyst among the lanthanide sulfides towards the degradation of organic dyes. A comparative catalytic study with morphologically different EuS revealed that the degradation rate changes with varying morphology and for all the dyes it strictly follows the decreasing order of sphere-like particles > cube-like particles > nanofibers.
- Ghosh, Abhisek Brata,Saha, Namrata,Sarkar, Arpita,Srivastava, Divesh N.,Paul, Parimal,Adhikary, Bibhutosh
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p. 102818 - 102827
(2015)
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- Liquid-phase synthesis of EuS nanocrystals and their physical properties
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The first EuS nanocrystals were prepared by the reaction of europium metal and HaS in liquid ammonia. X-ray diffraction (XRD) patterns and TEM images supported the formation of nanoscaled EuS crystals with average size of 20.4 nm. The nanocrystals showed blue shift compared with previously reported EuS films. The Curie point of EuS nanocrystals (16.6 K) was the same as that of the corresponding bulk compound, but a decreasing of magnetic moment was found because of the specific surface condition of the nanocrystals.
- Thongchant, Supitcha,Hasegawa, Yasuchika,Wada, Yuji,Yanagida, Shozo
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- Heteroligand lanthanide dialkyldithiocarbamate complexes with 1,10-phenanthroline: A new approach to synthesis and application for the preparation of sulfides
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A new simple method of synthesis of heteroligand complexes [Ln(Dalkdtc)3Phen] (Ln = Eu or Er; Dalkdtc is the dialkyldithiocarbamate ion, Phen is o-phenanthroline) in an aqueous solution is described; the possibility of using the complexes as initial reagents for the synthesis of rare-earth sulfides is shown.
- Ivanov,Korsakov,Formanovskii,Paramonov,Kuz'mina,Kaul'
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- Facile preparation of rare-earth semiconductor nanocrystals and tuning of their dimensionalities
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EuS and Gd2O2S nanocrystals with narrow size distribution are synthesized in high yields by the thermal decomposition of Eu(oleate)3 or Gd(oleate)3 in oleylamine using CS2 as the sulfur source. The dimensionalities of these nanocrystals can be facilely tuned by the addition of 1-dodecanethiol. The morphologies and crystal structures of EuS and Gd2O2S nanocrystals are characterized by TEM and XRD. The magnetic properties of the obtained nanocrystals are also investigated. The experimental results illustrate that CS2 is an effective sulfur source for the preparation of metal sulfide and lanthanide oxysulfide semiconductor nanocrystals.
- Lin, Hechun,Luo, Qianqian,Tong, Wen-Yi,Jiang, Chunli,Huang, Rong,Peng, Hui,Zhang, Lai-Chang,Travas-Sejdic, Jadranka,Duan, Chun-Gang
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- Molten alkali halide flux growth of an extensive family of noncentrosymmetric rare earth sulfides: Structure and magnetic and optical (SHG) properties
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Twenty new alkali rare earth thiosilicates and thiogermanates with the general formula ALnTS4 (A = alkali metal, Ln = lanthanide, and T = Si, Ge) were grown as X-ray diffraction-quality single crystals from molten alkali chloride fluxes. These include KNdSiS4, KPrSiS4, RbLnSiS4 (Ln = Ce, Pr, Nd, Gd, Tb, Dy, and Ho), RbLaGeS4, CsLnSiS4 (Ln = La, Pr, and Nd), and CsLnGeS4 (La, Ce, Pr, Nd, Eu, Gd, and Tb). Herein, we discuss the use of a molten chloride flux growth approach for the preparation of the title compounds and their structure determination via single-crystal X-ray diffraction. In addition, we comment on the magnetic properties of RbNdSiS4, CsNdSiS4, CsNdGeS4, and CsGdGeS4, which were found to be paramagnetic for T = 2?300 K and exhibited negative Weiss temperatures with no obvious antiferromagnetic transition down to 2 K. The optical properties of CsLaGeS4 and CsNdTS4(T = Si, Ge) were measured by UV?vis spectroscopy. Second harmonic generation measurements performed on CsLaGeS4 confirmed the crystallization of the compound in the noncentrosymmetric orthorhombic space group, P212121; CsLaGeS4 was found to be SHG-active with nearly half the intensity of α-SiO2 upon irradiation with a Nd:YAG 1064 nm laser, and a semiconductor exhibiting a band gap of 3.60 eV based on UV? vis diffuse reflectance measurements.
- Usman, Mohammad,Smith, Mark D.,Morrison, Gregory,Klepov, Vladislav V.,Zhang, Weiguo,Shiv Halasyamani,Loye, Hans-Conrad zur
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- A new structure type of the ternary sulfide Eu1.3Nb1.9S5
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The structure model for the Eu1.3Nb1.9S5 compound is determined based on high-resolution electron microscopy evidence. This compound crystallizes in a hexagonal unit cell with a = 8.8732(8) A and c = 23.45(1) A. Its structure is built up as an alternating sequence of trigonal-prismatic NbS2 layers of formula [Nb7S14] and [Nb(Eu3S4)2] slabs along the c-direction. In the [Nb(Eu3S4)2] block the stacking of two close-packed (Eu3S4) layers creates octahedral interstices formed by S atoms; these cavities are occupied by Nb cations. The model is compared with structures of other Eu-containing niobium sulfides, such as Eu0.167NbS2 and the misfit compound [(EuS)1.5]1.15NbS2.
- Khasanova,Van Tendeloo,Lebedev,Amelinckx,Grippa,Abakumov,Istomin,D'yachenko,Antipov
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- Magnetic and 151Eu M?ssbauer spectroscopic studies on rare earth bismuth sulfides, EuLnBiS4 (Ln = Eu, Gd)
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Ternary and quaternary rare earth bismuth sulfides EuLnBiS4 (Ln = Eu, Gd) have been investigated by X-ray diffraction, 151Eu M?ssbauer spectroscopy, and magnetic susceptibility measurements. Both compounds have the orthorhombic CaFe
- Wakeshima, Makoto,Hinatsu, Yukio
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- Effective optical faraday rotations of semiconductor EuS nanocrystals with paramagnetic transition-metal ions
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Novel EuS nanocrystals containing paramagnetic Mn(II), Co(II), or Fe(II) ions have been reported as advanced semiconductor materials with effective optical rotation under a magnetic field, Faraday rotation. EuS nanocrystals with transition-metal ions, EuS:M nanocrystals, were prepared by the reduction of the Eu(III) dithiocarbamate complex tetraphenylphosphonium tetrakis(diethyldithiocarbamate)europium(III) with transition-metal complexes at 300 C. The EuS:M nanocrystals thus prepared were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), inductively coupled plasma atomic emission spectroanalysis (ICP-AES), and a superconducting quantum interference device (SQUID) magnetometer. Enhanced Faraday rotations of the EuS:M nanocrystals were observed around 550 nm, and their enhanced spin polarization was estimated using electron paramagnetic resonance (EPR) measurements. In this report, the magneto-optical relationship between the Faraday rotation efficiency and spin polarization is discussed.
- Hasegawa, Yasuchika,Maeda, Masashi,Nakanishi, Takayuki,Doi, Yoshihiro,Hinatsu, Yukio,Fujita, Koji,Tanaka, Katsuhisa,Koizumi, Hitoshi,Fushimi, Koji
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- Magnetic properties and 151Eu Moessbauer effects of mixed valence europium copper sulfide, Eu2CuS3
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Ternary europium copper sulfide Eu2CuS3 have been investigated by X-ray diffraction, 151Eu Moessbauer spectroscopy, magnetic susceptibility, magnetization, and specific heat measurements. In this compound, Eu2+ and Eu3+ ions occupy two crystallographically independent sites. The 151Eu Moessbauer spectra indicate that the Eu2+ and Eu3+ ions exist in the molar ratio of 1:1, and the Debye temperatures of Eu2+ and Eu 3+ are 180 and 220K, respectively. In its magnetic susceptibility, the divergence between the zero-field cooled and field cooled susceptibilities appears below 3.4K. The specific heat has a λ-type anomaly at the same temperature. From the field dependence of magnetization at 1.8K, the Eu 2+ ion was found to be in the ferromagnetic state with the saturation magnetization MS=6.7μB.
- Furuuchi, Fumito,Wakeshima, Makoto,Hinatsu, Yukio
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- Synthesis of Mixed-Valent Lanthanide Sulfide Nanoparticles
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In targeting reduced valent lanthanide chalcogenides, we report the first nanoparticle synthesis of the mixed-valent ferromagnets Eu3S4 and EuSm2S4. Using divalent lanthanide halides with bis(trimethylsilyl)sulf
- Asuigui, Dane Romar C.,Atif, Rida,Biacchi, Adam J.,Glaser, Priscilla,Hight Walker, Angela R.,Morrison, Gregory,Stewart, Orlando,Stoll, Sarah L.,Swanson, Joel,zur Loye, Hans-Conrad
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- Photoluminescence properties of green-emitting ZnGa2S 4:Eu2+ phosphor
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Green-emitting ZnGa2S4:Eu2+ phosphors have been synthesized by solid state reaction. Their luminescence properties have been investigated by photoluminescence excitation and emission spectra, concentration quenching, thermal quenching and photoluminescence decay. The critical dopant concentration is found to be 0.05 mol of Eu2+ and the critical transfer distance of Eu2+ is calculated as 17 . The thermal quenching result suggests that the phosphor does not have good thermal-quenching property. Its chromaticity coordinates are very close to those of SrGa2S4:Eu2+. Because of their broadband absorption in the region 350-520 nm, the ZnGa2S4:0. 05Eu2+ phosphor can be a good green phosphor candidate for creating white light in phosphor-converted white LEDs, when combined with RB phosphors and a UV LED.
- Yu, Ruijin,Luan, Ruixin,Wang, Caifeng,Chen, Jingtao,Wang, Zhenxing,Moon, Byung Kee,Jeong, Jung Hyun
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- The first observation of the magnetic circular dichroism in EuS nanocrystals
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EuS nanocrystals were prepared by the liquid ammonia method. The size effect of EuS nanocrystals was observed in the magnetic measurements, the absorption spectra and the MCD spectra.
- Tsukahara, Yasunori,Kataoka, Tomoharu,Hasegawa, Yasuchika,Kaizaki, Sumio,Wada, Yuji
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- Benzene trisulfonic acid (H3BTS) as analogue of trimesic acid for building open frameworks: The first rare earth examples [La(BTS)(H 2O)5] and [RE(BTS)(H2O)4] (RE = Nd, Sm, Eu)
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The reaction of benzene 1,3,5-trisulfonic acid (H3BTS) with the hydroxides RE(OH)3 (RE = La, Nd, Sm, Eu) in aqueous solution afforded the sulfonates [La(BTS)(H2O)5] and [RE(BTS)(H 2O)4] (RE = Nd, Sm, Eu). Single crystal investigations were performed for the lanthanum and the europium compound, respectively. [La(BTS)(H2O)5] is triclinic [P|{1}, Z = 2, a = 783.18(6) pm, b = 1056.94(8) pm, c = 1082.38(8) pm, α = 114.860(2)°, β = 96.655(3)°, γ = 104.402(3)°] whereas [Eu(BTS)(H2O) 4] exhibits monoclinic symmetry [P21/n, Z = 4, a = 767.61(5) pm, b = 1730.2(1) pm, c = 1134.06(8) pm, β = 108.375(8)°]. Despite these crystallographic differences, the structural features of the lanthanum and europium compounds are very similar. They show the metal ions connected by BTS anions to layers that are further linked by hydrogen bonds. Interestingly, only two of the three sulfonate groups are connected to rare earth ions, whereas the third remains uncoordinated and acts as acceptor within the hydrogen bonds. According to powder XRD measurements the neodymium and samarium sulfonates are isotypic with the europium compound. The thermal analyses of the compounds show the dehydration in a temperature range between 100 and 300 °C, whereas the decomposition of the organic ligands takes place at temperatures as high as 550 °C. Thus the anhydrous sulfonates are much more stable than comparable salts of trimesic acid. The residues of the thermal decompositions were identified by XRD experiments.
- Mietrach, Andrea,Muesmann, Thomas W. T.,Zilinski, Christian,Christoffers, Jens,Wickleder, Mathias S.
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- Europium Pyridinethiolates: Synthesis, Structure, and Thermolysis
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The transmetalation reaction of Hg(SPy)2 (SPy = S-2-NC5H4) with Eu in pyridine gives the europium(II) pyridinethiolate coordination complex (py)4Eu(SPy)2 (1) in 96% isolated yield. The reaction of 1 with BIPY in THFresults in displacement of the pyridine ligands and the formation of the divalent coordination complex (BIPY)(THF)2Eu(SPy)2 (2). Low-temperature single-crystal X-ray diffraction experiments show that 1 and 2 are molecular 8 coordinate compounds. They are both intensely colored due to the presence of a visible europium-to-pyridine or europium-to-BIPY charge transfer (CT) absorption band. Trivalent [PEt4][Eu(SPy)4] (3) was prepared from the reaction of Eu/Hg amalgam with PySSPy in the presence of [PEt4][SPy]. X-ray diffraction analysis of 3 shows that all the pyridinechalcogenolate ligands are chelating the Eu(III) ion and there are three different eight coordinate isomers within the unit cell. Compound 3 is intensely colored because of a visible S-to-Eu CT absorption. At 500°C, 3 decomposes to give EuS and a mixture of PySSPy, PySPy, EtSPy, and SPEt3. Crystal data (Mo Kα, 153(5) K): 1. orthorhombic space groupPna2/1, a = 19.006(2) ?, b = 9.724(5) ?, c = 15.592(5) ?, Z= 4; 2, monoclinic space group Cc, a = 9.851(2) ?, b = 16.817(3) ?, c = 17.271(2) ?, β = 92.67(2)°, Z = 4; 3, monoclinic space group P21/n, a = 15.043(3) ?, b = 16.036(6) ?, c = 26.444(5) ?, β = 90.54(2)°, Z=4.
- Berardini, M.,Brennan, J.
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- Phase Equilibria in Systems DyCuS2–EuS and Cu2S?Dy2S3?EuS
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The phase diagram of system DyCuS2–EuS has been first constructed, and the phase equilibria in the Cu2S–Dy2S3–EuS triangle at 970 K have been studied. Compound EuDyCuS3 (1DyCuS2 : 1EuS), space group Pnma, a = 10.1901(3) ?, b = 3.9270(1) ?, c = 12.8468(3) ?, melts incongruently at 1727 ± 7 K according to the reaction: EuDyCuS3solid ? 0.17 SS EuS (90 mol % EuS, 10 mol % DyCuS2) + 0.83 liq (42 mol % EuS, 58 mol % DyCuS2), ΔH = 2.9 ± 0.6 kJ/mol; microhardness of the phase is 3080 ± 35 MPa. Compound EuDyCuS3 is transparent in the range 3000–1800 cm–1. In system DyCuS2–EuS, the solid solution (SS) based on EuS extends from 91 to 100 mol % at 1770 K and from 92 to 100 mol % at 1170 K. In γ-DyCuS2, 2 mol % EuS dissolves at 1487 K. The eutectic is formed between compounds DyCuS2 and EuDyCuS3 at 12 mol % EuS, T = 1487 ± 8 K. In system Cu2S?Dy2S3?EuS, 10 secondary systems have been isolated. At 970 K, tie-lines are located between compound EuDyCuS3 and solid solutions based on compounds β-Cu2S, EuS, DyCuS2, β-(DyCu3S3), and EuDy2S4; between DyCuS2 and the solid solution of α-Dy2S3, DyCuS2, and EuDy2S4.
- Ruseikina,Andreev
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- EuNdCuS3: Crystal structure of the high-temperature polymorph and properties
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The X-ray diffraction structure of the high-temperature polymorph of complex sulfide EuNdCuS3 is determined. The phase we prepared has an orthorhombic structure with the unit cell parameters a = 8.0648(3) ?, b = 4.0207(1) ?, c = 15.7924(3) ?, space group Pnma, Z = 4, Ba2MnS3 type structure. The sample is IR transparent in the range 1800-2800 cm-1. Thermal expansion coefficient is found to experience jumps, which are characteristic of phase transitions.
- Ruseikina,Solovyev,Andreev,Kislitsyn
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- Size Selective Synthesis of Surface-modified EuS Nanocrystals Using Pyridine and Their Physical Properties
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The particle size of EuS nanocrystals was gradually increased by addition of pyridine to the reaction mixture of europium metal and hydrogen sulfide in liquid ammonia. The size effect of EuS nanocrystals was found in the absorption spectra for the first t
- Thongchant, Supitcha,Hasegawa, Yasuchika,Wada, Yuji,Yanagida, Shozo
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- Exciton spectra of Eu1-xSrxS
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The reflection spectra are observed on (Eu, Sr)S single crystals obtained by using an arc-image furnace. Of the five reflection anomalies, the lower three structures are. assigned to the X-point excitons, and the upper doublet to the Γ-point exciton.
- Kaneko, Yoshio,Mitani, Tadaoki,Koda, Takao
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- Thermolysis of lanthanide dithiocarbamate complexes
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Polycrystalline lanthanide sulfide materials were formed at low temperatures using a single-source precursor based on the lanthanide dithiocarbamate complex. The synthesis temperatures are generally lower than standard solid state preparations, avoid toxic sulfurizing gases and provide a convenient route to prepare lanthanide chalcogenide nanoparticles. Depending on the reaction conditions and oxophilicity of the lanthanide, the sulfide material was formed with oxidized products including oxysulfides, oxysulfates and the oxide.
- Boncher, William L.,Regulacio, Michelle D.,Stoll, Sarah L.
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- Two rare-earth-based quaternary chalcogenides EuCdGeQ4 (Q = S, Se) with strong second-harmonic generation
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Two new rare-earth-based chalcogenides EuCdGeQ4 (Q = S, Se) have been designed and constructed by using Eu2+ and the classical NLO-active SBUs of [CdQ4] and [GeQ4]. They crystallize in a non-centrosymmetric Ama2 (no. 40) space group. Benefiting from the synergistic effects of [GeQ4] and highly distorted [CdQ4] tetrahedra, both compounds possess type-I phase-matching behaviour and large powder second harmonic generation (SHG) effects at 2.09 μm (2.6 and 3.8 × AgGaS2 for sulfide and selenide), as well as large direct band gaps (2.5 eV and 2.25 eV). Besides, they melt congruently at relatively low temperatures (997 °C for EuCdGeS4 and 882 °C for EuCdGSe4), which is suitable for bulk crystal growth by the Bridgman method. In addition, their electronic structures and some optical coefficients are calculated by first-principles.
- Xing, Wenhao,Wang, Naizheng,Guo, Yangwu,Li, Zhuang,Tang, Jian,Kang, Kaijin,Yin, Wenlong,Lin, Zheshuai,Yao, Jiyong,Kang, Bin
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supporting information
p. 17620 - 17625
(2019/12/23)
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- EuS-CdS and EuS-ZnS heterostructured nanocrystals constructed by Co-thermal decomposition of molecular precursors in the solution phase
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The EuS-CdS and EuS-ZnS heterostructured nanocrystals have been synthesized by a facile co-thermal decomposition method. The as-obtained nanoheterostructures possess unique optical-magnetic dual modal properties. This journal is
- Gong, Xueyun,Liu, Zhengqing,Yan, Dong,Zhao, Hongyang,Li, Na,Zhang, Xinyu,Du, Yaping
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supporting information
p. 3902 - 3907
(2015/04/27)
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- Crystal structure of EuLaCuS3
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The crystal structure of the EuLaCuS3complex sulfide synthesized for the first time has been solved by X-ray powder diffraction. Crystals are orthorhombic, space group Pnma, Ba2MnS3-type structure, a = 8.1297(3) ?, b = 4.0625(1) ?, c = 15.9810(4) ?, V = 527.80(3) ?3, Z = 4, and ρcalc = 5.669 g/cm 3. The La and Eu atoms are randomly disordered over two crystallographic positions with a coordination number of 7, and the Eu(La)-S bond lengths range from 2.892(6) to 3.078(6) ?. The CuS4 tetrahedra with Cu-S interatomic distances of 2.358(5)-2.40(1) ? form chains running along the b axis.
- Ruseikina,Solov'Ev,Andreev
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p. 574 - 578
(2012/07/14)
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- Synthesis and magnetic properties of Gd doped EuS nanocrystals with enhanced curie temperatures
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EuS nanocrystals (NCs) were doped with Gd resulting in an enhancement of their magnetic properties. New EuS and GdS single source precursors (SSPs) were synthesized, characterized, and employed to synthesize Eu1-xGd xS NCs by decomposition in oleylamine and trioctylphosphine at 290 °C. The doped NCs were characterized using X-ray diffraction, transmission electron microscopy, and scanning transmission electron microscopy, which support the uniform distribution of Gd dopants through electron energy loss spectroscopy (EELS) mapping. X-ray absorption spectroscopy (XAS) revealed the dopant ions in Eu1-xGdxS NCs to be predominantly Gd 3+. NCs with a variety of doping ratios of Gd (0 ≥ x C) was observed for samples with low Gd concentrations (x ≥ 10%) with a maximum TC of 29.4 K observed for NCs containing 5.3% Gd. Overall, the observed T C, Weiss temperature (θ), and hysteretic behavior correspond directly to the doping level in Eu1-xGdxS NCs and the trends qualitatively follow those previously reported for bulk and thin film samples.
- Selinsky, Rachel S.,Han, Jae Hyo,Morales Perez, Elvin A.,Guzei, Ilia A.,Jin, Song
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p. 15997 - 16005
(2011/01/10)
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- Synthesis and photophysical properties of EuS nanoparticles from the thermal reduction of novel Eu(III) complex
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EuS nanoparticles were synthesized by the thermal reduction of single source precursor (SSP), (PPh4)[Eu(S2-CNEt 2)4]·2H2O, under microwave irradiation. The average size of the EuS nanoparticles was found to be 8 nm (3-16 nm in size). The organic products on the EuS surface were observed by using FT-IR, NMR, and MS analyses. We have found that these are resulted from the chemical reactions of SSP and cover the nanocrystal surface. A thermal reaction of SSP gave EuS nanoparticles and the organic product (SCN(Et) 2). The organic product would make a dimmer, (Et)2NC(S)- (S)CN(Et)2, by the couping of the radicals formed in the thermal reaction and/or thiopolymer in the solution through the polymerization of the radicals. The effective surface modification by the organic products led to protection of the EuS surface, resulting in the formation of the strongly luminescent EuS nanoparticles at room temperature (emission peak = 350 nm, fwhm = 58 nm, emission quantum yield = 27 ± 5%).
- Hasegawa, Yasuchika,Okada, Yoshiko,Kataoka, Tomoharu,Sakata, Takao,Mori, Hirotaro,Wada, Yuji
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p. 9008 - 9011
(2008/10/09)
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- Thermochemistry of europium and dithiocarbamate complex Eu(C 5H8NS2)3(C12H 8N2)
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A solid complex Eu(C5H8NS2) 3(C12H8N2) has been obtained from reaction of hydrous europium chloride with ammonium pyrrolidinedithiocarbamate (APDC) and 1,10-phenanthroline (o-phen·H2O) in absolute ethanol. IR spectrum of the complex indicated that Eu3+ in the complex coordinated with sulfur atoms from the APDC and nitrogen atoms from the o-phen. TG-DTG investigation provided the evidence that the title complex was decomposed into EuS. The enthalpy change of the reaction of formation of the complex in ethanol, Δr H m θ(l), as -22.214±0.081 kJ mol-1, and the molar heat capacity of the complex, c m, as 61.676±0.651 J mol-1 K -1, at 298.15 K were determined by an RD-496 III type microcalorimeter. The enthalpy change of the reaction of formation of the complex in solid, Δr H m θ(s), was calculated as 54.527±0.314 kJ mol-1 through a thermochemistry cycle. Based on the thermodynamics and kinetics on the reaction of formation of the complex in ethanol at different temperatures, fundamental parameters, including the activation enthalpy (ΔH ≠ θ), the activation entropy (ΔS ≠ θ), the activation free energy (ΔG ≠ θ), the apparent reaction rate constant (k), the apparent activation energy (E), the pre-exponential constant (A) and the reaction order (n), were obtained. The constant-volume combustion energy of the complex, Δc U, was determined as -16937.88±9.79 kJ mol-1 by an RBC-II type rotating-bomb calorimeter at 298.15 K. Its standard enthalpy of combustion, Δc H m θ, and standard enthalpy of formation, Δf H m θ, were calculated to be -16953.37±9.79 and -1708.23±10.69 kJ mol -1, respectively. Springer-Verlag 2006.
- Chen,Meng,Shuai,Jiao,Gao,Shi
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p. 767 - 774
(2008/10/09)
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- Coinage metal lanthanide chalcogenides: I. Copper(I) lanthanide(III) sulfides of the composition CuMS2 (M = La - Nd, Sm, Gd, Tb) with the monoclinic A-type structure
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Single crystals of the ternary copper(I) lanthanide(III) sulfides with the composition CuMS2 (M = La - Nd, Sm, Gd, Tb) form within seven days at 800°C by oxidation of elemental copper and lanthanide metal with sulfur (molar ratio: 1:1:2) in evacuated silica tubes when equimolar quantitites of CsCl are present as flux. The crystal structures (monoclinic, P21/c, Z = 4; e.g. CuLaS2: a = 662.04(6), b = 730.89(6), c = 692.73(6) pm, β = 98.741(7)° and CuTbS2: a = 639.13(6), b = 700.02(6), c = 670.46(6) pm, β = 98.214(7)°) exhibit corrugated layers ∞2{[Cu(S1)3/3(S2)1/1] 3-} parallel to (100) which consist of vertex-linked pairs of [CuS4]7- tetrahedra sharing a common edge ([Cu 2S6]10-). Their three-dimensional cross-linkage is achieved by M3+ cations in monocapped trigonal prismatic coordination of seven S2- anions. The metal sulfur distances in the [CuS4]7- units cover with 230-233 (Cu-S2) and 231-238 (Cu-S1) as well as 241-248 (Cu-S1′) and 245-251 pm (Cu-S1″) a rather broad range, whereas those within the [MS7]11- polyhedra lie relatively closer together (M-S: 276-307 pm). The present work is the first comprehensive account of the knowledge acquired from X-ray single-crystal diffraction data for the whole isotypic series CuMS2 (M = La - Nd, Sm, Gd, Tb).
- Strobel, Sabine,Lauxmann, Petra,Schleid, Thomas
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p. 917 - 923
(2007/10/03)
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- Observation of anomalous Hall effect in thin film EuS
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We report on a study of the magnetotransport properties of EuS thin films grown by electron-beam deposition on (100) GaAs and (100) Si. The films are naturally doped due to a varying degree of sulfur deficiency. The sulfur deficiency and thus the doping level is found to vary systematically with the growth temperature. In these disordered self-doped materials we observe a large nonlinear component in the Hall effect at low temperatures. The close scaling between the Hall data and the magnetization implies that this effect is an anomalous Hall effect rather than a change of carrier concentration with magnetic field. The extracted anomalous Hall coefficient is found to scale linearly with the resistivity, indicating that it is due to skew scattering of the conduction electrons by the defects.
- Guilaran, I. J.,Read, D. E.,Kallaher, R. L.,Xiong, P.,Molnar, S. von,et al.
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- M(SCN)2 (M = Eu, Sr, Ba): Crystal structure, thermal behaviour, vibrational spectroscopy
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Single crystals of M(SCN)2 (M = Eu, Sr, Ba) have been obtained via metathesis of NaSCN and MCl2 (M = Eu, Sr, Ba) at 340°C. The isotypic crystal structures of the thiocyanates M(SCN)2 (C2/c, Z = 4, Eu: a = 979.3(2), b = 660.8(1), c = 815.7(2) pm, β = 91.58(3)°, Rall = 0.0245, Sr: a = 985.5(2), b = 662.9(2), c = 819.6(2) pm, β = 91.29(3)°, Rall = 0.0435, Ba: a = 1018.8(2), b = 687.2(1), c = 852.2(1) pm, β = 92.43(2)°, Rall = 0.0392) contain alternating layers of M2+ and SCN-. According to M(SCN)4/4(NCS)4/4 M2+ is eight-coordinated by four sulfur and four nitrogen atoms forming a square antiprism. Thermal investigations show that the compounds melt without decomposition. Vibrational spectroscopic investigations are presented and discussed. WILEY-VCH Verlag GmbH, 2001.
- Wickleder, Claudia
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p. 1693 - 1698
(2008/10/08)
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- On fluoride sulfides (MFS) of the lanthanides (M = La-Nd, Sm, Gd-Lu) with A- or PbFCl-type crystal structure
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By the reaction of the elemental lanthanides (M = La-Nd, Sm-Lu) with the respective trifluorides (MF3) and sulfur (S) in 2:1:3-molar ratios at 850°C, single-phase fluoride sulfides of the composition MFS can be obtained in evacuated, gas-tightly arc-welded niobium or tantalum capsules within a few days. Exceptions are europium and ytterbium which do not react to form the corresponding fluoride sulfides under these conditions. However, at least YbFS becomes accessible through this method if platinum serves as container material. With sodium chloride (NaCl) as a flux, the formation of hydrolysis-insensitive, platelet-shaped A-type single crystals with square cross-section and the formula MFS (M = La-Nd, Sm, Gd-Er) is possible. These are very suitable for structure refinement from X-ray diffraction data. In the PbFCl-analogous crystal structures (tetragonal, P4/nmm, Z = 2; LaFS: a = 404.38(4), c = 700.41(7) pm; CeFS: a = 400.13(3), c = 696.20(5) pm; PrFS: a = 396.27(3), c = 692.72(5) pm; NdFS: a = 393.89(3), c = 691.58(5) pm; SmFS: a = 388.36(3), c = 687.95(5) pm; GdFS: a = 383.45(3), c = 685.18(5) pm; TbFS: a = 381.02(3), c = 683.86(5) pm; DyFS: a = 378.48(2), c = 682.51 (4) pm; HoFS: a = 376.48(3), c = 681.92(5) pm; ErFS: a = 374.61(3), c = 681.34(5) pm), the M3+ cations are surrounded by nine anions (4F- and 5S2-) as monocapped square antiprisms. The anions themselves exhibit tetrahedral (F-) and square-pyramidal (S2-) cationic coordination, respectively, according to the Niggli formula ∞3{(M3+)(F-) 4/4(S2-)5/5}. In the case of TmFS, YbFS, and LuFS under analogous conditions, the hexagonal B- or trigonal C-type modifications form at first, which can be transformed eventually to the quenchable metastable tetragonal A-type polymorphs (TmFS: a = 372.86(5), c = 681.15(8) pm; YbFS: a = 371.08(5), c = 680.93(8) pm; LuFS: a = 369.37(5), c = 680.76(8) pm) at high pressure (20-60 kbar). WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2001.
- Schleid, Thomas,Grossholz, Hagen
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p. 2693 - 2699
(2008/10/08)
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