Large Magnetic Anisotropy and Magnetostriction in Thin Films of CoV${}_2$O${}_4$

Abstract

Spinel Cobalt Vanadate CoV${}_2$O${}_4$ has been grown on (001) SrTiO${}_3$ substrates. Using torque magnetometry experiments, we find that the previously observed temperature induced anisotropy change, where the easy axis changes from the out of plane [001] direction to a biaxial anisotropy with planar <100> easy axes, occurs in a gradual second-order structural phase transition. This work characterizes this transition and the magnetic anisotropies in the (001), (100), and (-110) rotation planes, and explores their field dependence up to 30~T. Below 80~K, hysteretic features appear around the hard axes, i.e., the out-of-plane direction in (-110) and (010) rotations and the planar <110> directions in (001) rotations. This is due to a Zeeman Energy that originates from the lag of the magnetization with respect to the applied magnetic field as the sample is rotated. The appearance of the hysteresis, which persist up to very high fields, shows that the anisotropy at low temperature is rather strong. Additionally, field dependent distortions to the symmetry of the torque response in increasing applied fields shows that magnetostriction plays a large role in determining the direction and magnitude of the anisotropy.

Main text: 9 pages and 6 figures; supplemental materials: 9 pages and 10 figures

References in corpus (6)

• Magnetic and orbital ordering in the spinel MnV2O4
• Magnetic order and ice rules in the multiferroic spinel FeV2O4
• Frustration-induced insulating chiral spin state in itinerant triangular-lattice magnets
• Orbital and magnetic transitions in geometrically-frustrated vanadium spinels -- Monte Carlo study of an effective spin-orbital-lattice coupled model --
• Enhanced Pressure Dependence of Magnetic Exchange in A2+[V2]O4 Spinels Approaching the Itinerant Electron Limit
• Strong competition between orbital-ordering and itinerancy in a frustrated spinel vanadate