Structural and Magnetic Properties of Fe₂P under Pressure at Low Temperature

Abstract

We have carried out X-ray diffraction and 57 Fe nuclear forward scattering using synchrotron radiation to study structural and magnetic properties of Fe 2 P under high pressure at low temperature. The lattice parameter ratio changes at 1.8 and 7.0 GPa as a function of pressure at 24 K without structural change, where the transition at 1.8 GPa corresponds to a ferromagnetic-to-antiferromagnetic one. We deduced the magnetic structures of Fe 2 P at 3 K and 2.5 GPa from refined hyperfine interaction parameters extracted from 57 Fe nuclear forward scattering spectra. Without external magnetic field where Fe 2 P is in the antiferromagnetic state, the magnetic structure is a complex one with a propagation vector along h100i. The distinct change of 57 Fe nuclear forward scattering spectra with external magnetic field along [001] indicates that a metamagnetic-like transition occurs below 5 kOe at 3 K and 2.5 GPa. With external magnetic field, the magnetic structures are not simple collinear ones. Furthermore, the magnetic-field-induced change in the magnetic structure occurs at around 40 kOe.

Synthesis of Hexagonal FeMnP Thin Films from a Single‐Source Molecular Precursor

“…The hexagonal phase of FeMnP has only previously been observed above 1200 °C and reverted to the orthorhombic phase upon cooling, preventing any subsequent characterization . The magnetic significance of compounds crystallizing in the hexagonal Fe 2 P‐type structure ( P 2 m ) has been established . For the first time, the magnetic properties of this metastable phase of FeMnP were measured with a magnetic property measurement system (MPMS) and are consistent with the theoretical values …”

“…[49] The magnetic significance of compounds crystallizing in the hexagonal Fe 2 P-type structure (P6 2m)h as been established. [50][51][52][53][54] For the first time, the magnetic properties of this metastablep hase of FeMnP were measured with am agnetic property measurement system (MPMS) and are consistent with the theoreticalv alues. [55] Experimental Section…”

Influence Mechanism of Mg2+ Doping on Electrochemical Properties of LiFePO4 Cathode Materials

“…This proves that Mg 2+ doping is of great benefit for the promotion of Fe 2 P production when the LFP is prepared using the solid-state method. As a metal phosphide, Fe 2 P demonstrates good metallicity and electronic conductivity, which means it is able to improve the electronic conductivity of the LFP cathode material. − Four-probe conductivity tests were conducted on the prepared LFP and Mg-LFP samples. The results revealed that the electronic conductivity of LFP samples is only 1.8939 × 10 –5 S/cm, whereas the electronic conductivity of Mg-LFP samples is 4.1317 × 10 –3 S/cm.…”

About the mechanical stability of MnFe(P,Si,B) giant-magnetocaloric materials

“…By using an experimental bulk modulus for Fe 2 P of K % 162 GPa [34][35][36][37] and an estimate of m % 0.3 to derive E % 194 GPa (and neglecting any compositional effect on the elastic parameters), the volumetric stresses caused by the relative volume change DV/V are 0.15, 0.42 and 0.24 GPa for samples A, B and C, respectively. For the MnFe(P,X) system, DV/V is tuned to be small and therefore the volumetric stresses during the magnetic transition are minimal.…”