Experimental determination of the temperature-and phase-dependent elastic constants of FeRh

Détermination expérimentale des constantes élastiques de FeRh en fonction de la température et de la phase magnétique

D. Ourdani (1, 2, 3) , Aloïs Castellano (4, 5) , Ashwin Kavilen Vythelingum (1, 2) , Jon Ander Arregi (6) , Vojtěch Uhlíř (6) , Bernard Perrin (1, 7) , M. Belmeguenai (3) , Y. Roussigné (3) , Catherine Gourdon (1, 2) , Matthieu Jean Verstraete (5, 4, 8) , L. Thevenard (1, 2)

1 INSP - Institut des Nanosciences de Paris
2 INSP-E13 - Nanostructures : Élaboration, effets quantiques et magnétisme
3 LSPM - Laboratoire des Sciences des Procédés et des Matériaux
4 ETSF - European Theoretical Spectroscopy Facility
5 Université de Liège
6 CEITEC MU - Central European Institute of Technology [Brno]
7 INSP-E14 - Acoustique et optique pour les nanosciences et le quantique
8 Universiteit Utrecht

The elastic constants of an epitaxial film of FeRh have been determined experimentally in both ferromagnetic (FM) and antiferromagnetic (AF) phases, using a combination of Brillouin light scattering and picosecond acoustics experiments. The C11 constant is noticeably larger in the FM phase than in the AF phase, while C12 and C44 are both lower, leading to larger Rayleigh wave velocities in the FM phase than in the AF phase. The elastic constants were calculated numerically using first principles anharmonic modeling and machine-learned interatomic potentials. We find that using a temperature-dependent effective potential is indispensable to correctly reproduce the experimental values to within 80 to 100%. The accurate knowledge of the temperature- and phase-dependencies of the elastic constants of crystalline FeRh are valuable ingredients for the predictive modeling of the acoustic and magneto-acoustic properties of this magnetostrictive material.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

D. Ourdani, Aloïs Castellano, Ashwin Kavilen Vythelingum, Jon Ander Arregi, Vojtěch Uhlíř, et al.. Experimental determination of the temperature-and phase-dependent elastic constants of FeRh. 2024. ⟨hal-04526444⟩