The comparative catalytic activities of iron phosphides, FexP (x = 1–3), have been established with phase-pure material grown by chemical vapor deposition (CVD) from single-source organometallic precursors. This is the first report of the preparation of phase-pure thin films of FeP and Fe2P, and their identity was established with scanning-electron microscopy, X-ray photoelectron spectroscopy, and powder X-ray diffraction. All materials were deposited on fluorine-doped tin oxide (FTO) for evaluation of their activities toward the hydrogen evolution reaction (HER) of water splitting in 0.5 M H2SO4. HER activity follows the trend Fe3P > Fe2P > FeP, with Fe3P having the lowest overpotential of 49 mV at a current density of 10 mA cm–2. Density functional theory (DFT) calculations are congruent with the observed activity trend with hydrogen binding favoring the iron-rich terminating surfaces of Fe3P and Fe2P over the iron-poor terminating surfaces of FeP. The results present a clear trend of activity with iron...

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Effects of Catalyst Phase on the Hydrogen Evolution Reaction of Water Splitting: Preparation of Phase-Pure Films of FeP, Fe2P, and Fe3P and Their Relative Catalytic Activities

Photoemission and band structure of crystalline and amorphous iron phosphoborides

The Mossbauer spectrum of amorphous iron-phosphorus has been measured for alloys having compositions ranging from 15 to 25.8 at% phosphorus. Measurements were made at ambient temperature and also above the Curie temperature. The Curie temperature was measured by an induction method and increased linearly from 280 to 300°C with decreasing phosphorus content. The results indicated a large number of different iron sites having the same compositional short-range order as the crystal.

A Mössbauer study of amorphous iron-phosphorus alloys

The three partial interference functions of a Co-P alloy, which are simply related to the static pair-correlation functions, have been determined using a polarized neutron technique which may be extended to other binary amorphous ferromagnets. The equations necessary for the interpretation of the measurements are presented and discussed.

Determination of the three partial interference functions of an amorphous cobalt-phosphor ferromagnet by polarized-neutron scattering

Some applications of NMR to the study of magnetically-ordered materials with emphasis on the short-range order in (Fe-B)-based crystalline and amorphous alloys

Magnetization, Mossbauer and neutron diffraction measurements have been made on powdered and single crystal samples of Fe3P. The average moments on the iron sites are 2.12 mu B, 1.25 mu B and 1.83 mu B. The Mossbauer spectra indicate a splitting of the moments of approximately 0.1 mu B for the atoms on each iron site. The observed magnetic hyperfine fields are 28.4 T and 27.3 T for FeI, 17.3 T and 17.5 T for FeII and 23.0 T and 25.0 T for FeIII at room temperature.

https://iopscience.iop.org/article/10.1088/0022-3719/7/7/026/pdf

Studies of the magnetic structure of Fe3P

Mossbauer data on the magnetic properties of FesSiBz are presented and compared with measurements on Fe5PB2, MnsPBz and MnsSiBz. The introduction of boron on the silicon position leads to an increase in the magnetic hyperfine field at neighbouring iron nuclei. 1. Introduction. - In an realier study, the magnetic and crystallographic properties of Fe,PB2 were investigated (I). Fe5PB2 was shown to be a simple ferromagnet with the tetragonal axis as the direction of easy magnetization. Furthermore, the Mossbauer data indicated that in non-stoichiometric Fe5PB2 part of the phosphorus positions are occupied by boron atoms and this has a rather large effect on the atomic moment on neighbouring iron atoms. A similar increase in atomic moment, and consequently magnetic hyperfine field at the nucleus, was found for iron in Fe,P, -,B, (2) and in order to see if the same situation prevails for Si/B substitution it was decided to investigate non- stoichiometric Fe5SiB2, which is isostructural with Fe5PB2 (3). The results are compared with recently available magnetic data for the corresponding manga- nese compounds.

R. Wappling

Papers

Studies of the magnetic structure of Fe3P

MAGNETIC PROPERTIES OF Fe,SiB2 AND RELATED COMPOUNDS