Effect of pressure on the electronic and magnetic properties of CdV$_2$O$_4$: Density functional theory studies

Abstract

We investigate the effect of pressure on the electronic and magnetic states of CdV$_2$O$_4$ by using ab initio electronic structure calculations. The Coulomb correlation and spin-orbit coupling play important role in deciding the structural, electronic and magnetic properties of the compound. The total magnetic moment of V ion is found to be $\sim$1.3 $\mu_B$ and making an angle of $\sim$9.5 degree with the z-axis. In the tetragonal phase, the ground state is the orbital ordered state where V $d_{xz}$ and $d_{yz}$ obtitals are mainly occupied at the neighbouring sites. This work predicts the electronic phase transition from orbital-ordered-insulator to orbital-ordered-metal to orbital-disordered-metal with increasing pressure. The pressure induced broadening of lower and upper Hubbard bands gives rise to metal-insulator transition above 35 GPa. The simple mean-field theory used in the present work is able to describe the pressure dependent variation of the antiferromagnetic transition temperature suggesting the applicability of the method in the study of the magnetic behaviour of similar geometrically frustrated systems.