Cu2S-EuS phase diagram1

Andreev,Ruseikina

, p. 1502 - 1507 (2012)

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.

Heterometallic Eu/M(II) Benzenethiolates (M = Zn, Cd, Hg): Synthesis, Structure, and Thermolysis Chemistry

Brewer, Meggan,Lee, Jongseong,Brennan, J. G.

, p. 5919 - 5924 (1995)

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.

Sulfurization of rare-earth oxides with CS2

Sato, Nobuaki,Shinohara, Genki,Kirishima, Akira,Tochiyama, Osamu

, p. 669 - 672 (2008)

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.

Parkin, I. P.,Fitzmaurice, J. C.

, p. 1569 - 1572 (1993)

Regularities of the property changes in the compounds EuLnCuS3 (Ln = La-Lu)

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.

, (2021)

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.

Crystal structure of EuCeCuS3

Ruseikina

, p. 1403 - 1407 (2016)

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 ?.

Physical and optical properties of the quaternary sulfides SrCu2MS4 and EuCu2MS4 (M=Ge and Sn)

Llanos, Jaime,Mujica, Carlos,Sanchez, Victor,Pena, Octavio

, p. 78 - 82 (2003)

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.

Synthesis, structure, and properties of EuErCuS3

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.

, p. 779 - 788 (2019)

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.

Beck, G.,Nowacki, W.

, p. 495 - 495 (1938)

Synthesis and properties of ZnS-EuS films grown from volatile complex compounds

Bessergenev,Ivanova,Kovalevskaya,Vasilieva,Varand,Zemskova,Larionov,Kolesov,Ayupov,Logvinenko

, p. 1403 - 1410 (1997)

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.

Phase diagrams of sections in the EuS-Cu2S-Nd2S 3 system

Andreev,Ruseikina,Solov'Ev

, p. 792 - 797 (2011)

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.

Luminescence properties of Ca1-xSrx(Ga 1-yAly)2S4: Eu2+ and their potential application for white LEDs

Yu, Ruijin,Wang, Jing,Zhang, Mei,Yuan, Haibin,Ding, Weijia,An, Yun,Su, Qiang

, p. J290-J292 (2008)

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).

Synthesis and crystal structure of two new oxychalcogenides: Eu5V3S6O7 and La10Se14O

Meerschaut,Lafond,Palvadeau,Deudon,Cario

, p. 1895 - 1905 (2002)

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.

Liquid-phase synthesis of EuS nanocrystals and their physical properties

Thongchant, Supitcha,Hasegawa, Yasuchika,Wada, Yuji,Yanagida, Shozo

, p. 2193 - 2196 (2003)

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.

Heteroligand lanthanide dialkyldithiocarbamate complexes with 1,10-phenanthroline: A new approach to synthesis and application for the preparation of sulfides

Ivanov,Korsakov,Formanovskii,Paramonov,Kuz'mina,Kaul'

, p. 670 - 672 (2002)

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.

Molten alkali halide flux growth of an extensive family of noncentrosymmetric rare earth sulfides: Structure and magnetic and optical (SHG) properties

Usman, Mohammad,Smith, Mark D.,Morrison, Gregory,Klepov, Vladislav V.,Zhang, Weiguo,Shiv Halasyamani,Loye, Hans-Conrad zur

, p. 8541 - 8550 (2019)

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.

Sato, M.,Adachi, G.,Shiokawa, J.

, p. 337 - 341 (1980)

Kaldis, E.

, p. 3 - 18 (1972)

Effective optical faraday rotations of semiconductor EuS nanocrystals with paramagnetic transition-metal ions

Hasegawa, Yasuchika,Maeda, Masashi,Nakanishi, Takayuki,Doi, Yoshihiro,Hinatsu, Yukio,Fujita, Koji,Tanaka, Katsuhisa,Koizumi, Hitoshi,Fushimi, Koji

, p. 2659 - 2666 (2013)

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.

Synthesis of Mixed-Valent Lanthanide Sulfide Nanoparticles

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

, (2021)

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

Photoluminescence properties of green-emitting ZnGa2S 4:Eu2+ phosphor

Yu, Ruijin,Luan, Ruixin,Wang, Caifeng,Chen, Jingtao,Wang, Zhenxing,Moon, Byung Kee,Jeong, Jung Hyun

, p. J188-J192 (2012)

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.

The first observation of the magnetic circular dichroism in EuS nanocrystals

Tsukahara, Yasunori,Kataoka, Tomoharu,Hasegawa, Yasuchika,Kaizaki, Sumio,Wada, Yuji

, p. 203 - 206 (2006)

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.

Europium Pyridinethiolates: Synthesis, Structure, and Thermolysis

Berardini, M.,Brennan, J.

, p. 6179 - 6185 (1995)

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.

EuNdCuS3: Crystal structure of the high-temperature polymorph and properties

Ruseikina,Solovyev,Andreev,Kislitsyn

, p. 1109 - 1114 (2014)

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.

Exciton spectra of Eu1-xSrxS

Kaneko, Yoshio,Mitani, Tadaoki,Koda, Takao

, p. 1029 - 1030 (1979)

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.

Two rare-earth-based quaternary chalcogenides EuCdGeQ4 (Q = S, Se) with strong second-harmonic generation

Xing, Wenhao,Wang, Naizheng,Guo, Yangwu,Li, Zhuang,Tang, Jian,Kang, Kaijin,Yin, Wenlong,Lin, Zheshuai,Yao, Jiyong,Kang, Bin

supporting information, p. 17620 - 17625 (2019/12/23)

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.