26508-33-8Relevant academic research and scientific papers
Helical magnetic structure and hyperfine interactions in FeP studied by 57Fe M?ssbauer spectroscopy and 31P NMR
Sobolev, Alexey V.,Presniakov, Igor A.,Gippius, Andrey A.,Chernyavskii, Ivan V.,Schaedler, Martina,Buettgen, Norbert,Ibragimov, Sergey A.,Morozov, Igor V.,Shevelkov, Andrei V.
, p. 277 - 285 (2016)
We report results of 57Fe M?ssbauer and 31P NMR studies of a phosphide FeP powder sample performed in a wide temperature range including the point (TN ≈ 120 K) of magnetic phase transitions. The 57Fe M?ssbauer spectra at low temperatures T N present a very complex Zeeman pattern with line broadenings and sizeable spectral asymmetry. It was shown that the change of the observed spectral shape is consistent with the transition into a space-modulated helicoidal magnetic structure. Analysis of the experimental spectra was carried out assuming an anisotropy of the magnetic hyperfine field Hhf at the 57Fe nuclei when the Fe3+ magnetic moment rotates with respect to the principal axis of the electric field gradient (EFG) tensor. The obtained large temperature independent anharmonicity parameter m ≈ 0.96 of the helicoidal spin structure results from easy-axis anisotropy in the plane of the iron spin rotation. It was assumed that a very low maximal value of Hhf(11 K) ≈ 36 kOe and its high anisotropy ΔHanis(11 K) ≈ 30 kOe can be attributed to the stabilization of iron cations in the low-spin state (SFe = 1/2). The 31P NMR measurements demonstrate an extremely broad linewidth reflecting the spatial distribution of the transferred internal magnetic fields of the Fe3+ ions onto P sites in the magnetically ordered state.
FeP and FeP2 nanowires for efficient electrocatalytic hydrogen evolution reaction
Son, Chang Yong,Kwak, In Hye,Lim, Young Rok,Park, Jeunghee
, p. 2819 - 2822 (2016)
We report achieving of efficient electrocatalytic hydrogen evolution reaction using composition-controlled iron phosphide (FeP and FeP2) nanowires. The respective Tafel slopes of nanowire arrays were 39 and 37 mV dec-1 in 0.5 M H2SO4, and 75 and 67 mV dec-1 in 1 M KOH. The richer P composition produced excellent electrocatalytic efficiency.
Superconductivity of the "1 1 1" type iron pnictide LiFeP
Deng,Wang,Liu,Zhang,Lv,Zhu,Yu,Jin
, p. S309-S310 (2010)
We report studies on a new iron based LiFeP superconductor. The compound takes the same structure to LiFeAs containing a "FeP" conduction layer. Superconductivity was achieved up to 6 K. The new superconductor is featured with itinerant behavior at normal
A general methodology for the synthesis of transition metal pnictide nanoparticles from pnictate precursors and its application to iron-phosphorus phases
Stamm, Kimber L.,Garno, Jayne C.,Liu, Gang-yu,Brock, Stephanie L.
, p. 4038 - 4039 (2003)
Nanoparticles of iron phosphide have been prepared through a new strategy involving the reductive annealing of nanoparticulate iron phosphate precursors cast onto atomically flat mica surfaces. This route appears to be general for a range of transition metals and pnicogens and avoids the use of highly toxic and pyrophoric agents such as Pn(SiMe3)3 (Pn = P, As), which are commonly employed in the synthesis of pnictide nanoparticles. Copyright
The Enhanced CO Tolerance of Platinum Supported on FeP Nanosheet for Superior Catalytic Activity Toward Methanol Oxidation
Wang, Yajing,Du, Chunyu,Sun, Yongrong,Han, Guokang,Kong, Fanpeng,Yin, Geping,Gao, Yunzhi,Song, Ying
, p. 36 - 43 (2017)
The inferior CO-like intermediates tolerance of Pt nanoparticle greatly hampered the MOR activity and durability. To alleviate this issue, tremendous efforts have been made to create oxygen-containing groups on neighbouring Pt site for oxidizing the poisonous carbonaceous species. Given this, two-dimensional FeP nanosheet with excellent HER activity was utilized as support and cocatalyst. FeP nanosheet with special Feδ+ and Pδ? active sites was conductive to mass transfer, fast charge transfer and facilitating water dissociation for generating OH species to removal CO-like intermediates on Pt sites. The XRD, XPS, SEM and TEM analysis demonstrated that the Pt nanoparticle with an average size of 3.68 nm was successfully deposited on the FeP nanosheet surface. The methanol oxidation experiments in acidic medium revealed that the as-prepared binary Pt/FeP nanosheet hybrid exhibited superior MOR activity with enhanced anodic peak current density of 0.994 mA/cm2, which was 2.74-fold greater than that of commercial Pt/C, and the intensive CO oxidation peak potential was negatively shifted about 100 mV with respect to that of Pt/C. The better CO tolerance of Pt/FeP nanosheet hybrid might be attributed to cooperative effect from down-shifted d-band center of Pt, abundant hydroxyls on the Pt/FeP and special activity of Feδ+ and Pδ?. In addition, this hybrid electrocatalyst also showed relatively higher HER activity compared with that of Pt/C. This study provides a promising application of metal phosphide in methanol oxidation for enhancing CO resistance capability of Pt-based catalyst.
CVD growth of high density SWNTs network on surface using iron phosphide nanorods as catalyst precursor
Huang, Shaoming,Bai, Yanhu,Chen, Jinagyin,Wang, Shun,Wang, Zhimin
, p. 49 - 53 (2008)
In this Letter, we demonstrated that FeP nanorods synthesized by thermal decomposition of iron carbonyl under the protection of surfactants can be used as catalyst for SWNTs growth. The domains structure of FeP nanorods or uniform dispersion of the nanorods by self-assembly on surface can be controlled by chemical modification of the surface and concentration of the nanorods solution. Domain structure of SWNTs network or extremely high density SWNTs film with uniform diameter can be generated using carbon monoxide chemical vapor deposition (CO-CVD). The uniform diameter of the SWNTs is believed to be due to the in situ formation of uniform Fe nanoparticles from the decomposition of FeP nanorods at high temperature. The use of nanorods or nanowires as catalyst precursor for SWNTs growth could open a new method to generate extremely high density SWNTs with uniform diameter for SWNTs-based nanoelectronics device applications.
De Haas-van alphen effect of FeP in double helical magnetic state
Nozue, Tatsuhiro,Kobayashi, Hisao,Kimura, Noriaki,Aoki, Haruyoshi,Kamimura, Takashi
, p. 192 - 198 (2001)
The de Haas-van Alphen (dHvA) effect has been investigated on high-quality single crystals of FeP in a double helical magnetic state with a 5c period in the magnetic fields up to 14 T and at temperatures down to 0.42 K. Single crystals were grown by the chemical transport technique using iodine as the transport agent. Nineteen branches were observed in three crystallographic planes (100), (010) and (001), and analyzed with simple analytic equations for the Fermi surfaces. Many of the dHvA branches have a characteristic angular dependence and are found to correspond to the orbits on surfaces beyond the Brillouin zone in the magnetic state which is reduced to 1/5 of the non-magnetic one with the MnP-type along the [001] direction. These branches originate from the orbits caused by a magnetic breakdown phenomenon under high fields. Cyclotron mass ratios were obtained to be up to 5.9, whereas the electronic specific heat coefficient is rather small, 2.86 mJK-2mol-1.
Solution-Phase Synthesis of Single-Crystalline Iron Phosphide Nanorods/Nanowires
Qian, Cheng,Kim, Franklin,Ma, Lei,Tsui, Frank,Yang, Peidong,Liu, Jie
, p. 1195 - 1198 (2004)
A solution-phase route for the preparation of single-crystalline iron phosphide nanorods and nanowires is reported. We have shown that the mixture of trioctylphosphine oxide (TOPO) and trioctylphosphine (TOP), which are commonly used as the solvents for semiconductor nanocrystal synthesis, is not entirely inert. In the current process, TOP, serving as phosphor source, reacts with Fe precursors to form FeP nanostructures with large aspect ratios. In addition, the experimental results show that both TOP and TOPO are necessary for the formation of FeP nanowires and their ratio appears to control the morphology of the produced FeP structures. A possible growth mechanism is discussed.
De Haas-van Alphen effect and transverse magnetoresistance in FeP
Nozue, Tatsuhiro,Saito, Akira,Kobayashi, Hisao,Yamagami, Hiroshi,Kamimura, Takashi
, p. 1509 - 1510 (2000)
The 3d transition metal monopnictides show various interesting electric and magnetic properties. In this study, we have measured the dHvA effect and the transverse magnetoresistance in FeP which has the MnP-type structure and is antiferromagnetic below 12
Fe65.5Cr4Mo4Ga4P12 C5B5.5 BMGs: Sample preparation, thermal stability and mechanical properties
Stoica,Eckert,Roth,Yavari,Schultz
, p. 171 - 175 (2007)
Bulk amorphous Fe-based alloys with the nominal composition Fe65.5Cr4Mo4Ga4 P12C5B5.5 have been obtained by copper mold casting in different shapes: cylindrical rods with diameters up to 3 mm, rectangular bars of 2 mm × 2 mm and discs of 10 mm diameter and 1 mm thickness. These alloys exhibit good soft magnetic properties, characterized by low coercivity and high saturation magnetization. Besides the magnetic properties, the Fe65.5Cr4Mo4Ga4 P12C5B5.5 bulk metallic glass (BMG) shows a high glass transition temperature Tg, as well as a high crystallization temperature Tx, with an extension of the supercooled liquid region of around 65 K. The mechanical behavior was investigated by compression and Vickers hardness tests. The fracture strength for the as-cast samples σf is 2.8 GPa and the fracture strain εf is 1.9%. Upon annealing at 715 K for 10 min, i.e. at a temperature below the calorimetric glass transition, the fracture strain drops to 1.6% and no plastic deformation is observed. The Vickers hardness HV for the as-cast samples is about 885, and increases to 902 upon annealing. The fracture behavior of these Fe-based bulk glassy alloys is significantly different in comparison with the well-studied Zr-, Cu- or Ti-based good glass-formers. The fracture is not propagating along a well-defined direction and the fractured surface looks irregular. Instead of veins, the glassy alloy develops a high number of microcracks.
