Growth and magnetic properties of stoichiometric and site disordered single crystalline MgV2O4

We have grown several single crystals of the highly frustrated S 1 spinel MgV2O4 using different starting compositions and growth conditions. From our study of their physical properties by magnetic susceptibility, heat capacity, and single crystal neutron and powder diffraction measurements, we observe that a minute amount of disorder suppresses the structural and magnetic phase transitions. As little as 3 disorder in the octahedral site introduced random strain, which was enough to completely suppress the transitions and induce a spin glass phase at low temperatures. We believe that the reason is spin exchange disorder rather than disorder in the weakly diluted magnetic lattice. Our results also show that the MgO V2O3 system is a solid solution that melts slightly incongruently, and we demonstrate that by using an optimized solvent in the traveling solvent floating zone configuration a large single crystal l 25 mm, d 6 mm with a homogeneous composition, free of site disorders can be grown