Ab initio study of FeRh alloy properties

JIMENEZ M. J.; SCHVVAL, A. B.; CABEZA G. F.

COMPUTATIONAL MATERIALS SCIENCE

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2019

0927-0256

In this work the structural, energetic, thermodynamic, magnetic and thermoelectric properties of FeRh alloy havebeen studied using first-principles calculations. The structural and magnetic results obtained for the FM phase arein agreement with experimental and other theoretical calculated values (local magnetization of about 3 μB and1 μB for Fe and Rh atoms respectively). The transition AFM to the FM state is accompanied by a 2.4% increasein the volume of the cell and by 9.6% in the Fe spin magnetic moment. The characterization of the AFM phaseshows a distortion of the cubic and tetragonal cell to the orthorhombic solving the instabilities observed in thephonon band structures curves of the corresponding to cubic structure. The stability of the AFM configurationswas corroborated with molecular dynamics (MD) simulations. The magnitude of the Seebeck coefficient increaseswith the temperature at a certain chemical potential. While the magnitude of the electrical conductivity doesnot present meaningful changes with the temperature in the selected values, the thermal conductivity increaseswith the temperature. Another consequence of the AFM to FM transition is the drop of the resistivity ρ in theFM phase as compared to the AFM state. Based on the results obtained using MD simulations from stable AFMconfigurations and the results of entropy changes, the configuration AFM-B (type I) could be identified as themost favorable in achieving the metamagnetic phase transition.