Stress-tailoring magnetic anisotropy of V${}_2$O${}_3$/Ni bilayers

Abstract

We report on a temperature-driven reversible change of the in-plane magnetic anisotropy of V${}_2$O${}_3$/Ni bilayers. This is caused by the rhombohedral to monoclinic structural phase transition of V${}_2$O${}_3$ at $T_C$ = 160 K. The in-plane magnetic anisotropy is uniaxial above $T_C$, but as the bilayer is cooled through the structural phase transition, a secondary magnetic easy axis emerges. Ferromagnetic resonance measurements show that this change in magnetic anisotropy is reversible with temperature. We identify two structural properties of the V${}_2$O${}_3$/Ni bilayers affecting the in-plane magnetic anisotropy: (1) a growth-induced uniaxial magnetic anisotropy associated with step-like terraces in the bilayer microstructure and (2) a low-temperature strain-induced biaxial anisotropy associated with the V${}_2$O${}_3$ structural phase transition. Magnetoresistance measurements corroborate the change in magnetic anisotropy across the structural transition and suggest that the negative magnetostriction of Ni leads to the emergence of a strain-induced easy-axis. This shows that a temperature-dependent structural transition in V${}_2$O${}_3$ may be used to tune the magnetic anisotropy in an adjacent ferromagnetic thin film.

9 pages, 8 figures

References in corpus (1)

• Growth-Induced In-Plane Uniaxial Anisotropy in V${}_2$O${}_3$/Ni Films