Frustrated magnetism and magnetic reversal in inverse spinel Co$_{2}$VO$_{4}$*

Vanadium oxide spinels with formula $A$V$_{2}$O$_{4}$ ($A$ = Co, Fe, Mn, etc.) have attracted much interest due to their intriguing physical properties but little attention has been paid to inverse vanadium oxide spinels of the form, $A_{2}$VO$_{4}$ ($A$ = Co or Fe). Here we report magnetization, X-ray and neutron diffraction, and XMCD measurements on high quality polycrystalline Co$_{2}$VO$_{4}$ sample that has been known as a magnetization-reversal system. Magnetic susceptibility measurements show a magnetic transition at $T_N$ = 165~K, with features that dramatically change below 100 K as external field ($H$) is increased. Interestingly, for $H \le 0.25$~T and $T < 75$~K, magnetization reversal is observed in field-cooled measurements which is also confirmed by the XMCD measurements that reveal a spin-flop of the B-site Co and V $L$-edges. X-ray and neutron diffraction measurements confirm its $Fd\bar{3}m$ symmetry, which remains unchanged from 300 to 2~K and indicate a single magnetic transition at $T_N = 165$~K. Analysis of the detailed neutron powder diffraction measurements of the magnetic structure will also be shown.