Effects of applied pressure in ZnV2 O4 and evidences for a dimerized structure

The series of V spinels [A(2+)] V-2 O-4 (A = Cd, Mn, Zn, Mg) provides an opportunity to tune the V-V distance continuously, in the frustrated pyrochlore lattice of the spinel. This system has been shown to approach the metallic state when V-V distance is reduced. The proximity to the transition leads to a dimerized structure in ZnV2 O-4 caused by lattice instabilities. A different manner to tune the V - V distance of this structure is to fix the A(2+) cation (in our case, Zn) and apply pressure. We have analyzed the evolution of the electronic structure of the system in the dimerized state. Such structure prevents the system to present a metallic phase at moderate pressures. We have also calculated the transport properties in a semiclassical approach based on Boltzmann transport theory. Our results support the validity of this structural distortion by providing a nice fit with experimental measurements. (C) 2011 American Institute of Physics. [doi:10.1063/1.3565410]