Magnetic Field Induced Transition in Vanadium Spinels

TL;DR

This study investigates magnetic field-induced phase transitions in vanadium spinels, revealing a quantum phase transition in MgV2O4 and polarization suppression in CdV2O4, explained by strong spin-orbit coupling and local crystal fields.

Contribution

It provides the first detailed analysis of magnetic and electric transitions in vanadium spinels under high magnetic fields considering spin-orbit coupling effects.

Findings

Magnetization jump at 40 T in MgV2O4 indicating a quantum phase transition.

Suppression of electric polarization in CdV2O4 during the transition.

Modeling shows local trigonal crystal field effects explain observed phenomena.

Abstract

We study vanadium spinels $A$V$_2$O$_4$ ($A$ = Cd, Mg) in pulsed magnetic fields up to 65 T. A jump in magnetization at $\mu_0 H \approx$ 40 T is observed in the single-crystal MgV$_2$O$_4$, indicating a field induced quantum phase transition between two distinct magnetic orders. In the multiferroic CdV$_2$O$_4$, the field-induced transition is accompanied by a suppression of the electric polarization. By modeling the magnetic properties in the presence of strong spin-orbit coupling characteristic of vanadium spinels, we show that both features of the field-induced transition can be successfully explained by including the effects of the local trigonal crystal field.