Magnetic properties and stability of Cu3V2O8 compound in the different phases

Abstract

The magnetic and thermodynamic properties of Cu3V2O8 compound in four structures (P−1, P21/c, P21/m and Cmca) are reported. The calculations are performed by using the Full-Potential Local Orbital Minimum Basis (FPLO) and Vienna ab initio Simulation Package (VASP) methods. We have applied the local density approximation (LDA) with the generalized gradient corrections (GGA). The effect of electron correlations was also included in GGA+U approximation. The thermodynamic properties were obtained in the quasi-harmonic Debye–Grüneisen model using the equation of states (EOS) in the form of Poirier–Tarantola. Our ab-intio results indicate that α (P−1) phase is stable below 1.87GPa, β (P21/c) exists in the region 1.87<P<7.42GPa and γ (Cmca) is observed above P=7.42GPa. Our results have shown that in GGA and GGA+U the antyferromagnetic configuration is stable in P−1, P21/c and P21/m structures. The calculated values of gaps in P−1, P21/c crystal structures are close to the experimental data.