Ab initio study of thermophysical properties of β-PbO2 under high temperature and pressure

We report a theoretical investigation on the finite temperature thermophysical properties of tetragonal lead dioxide (beta-PbO2) material using ab initio calculations in the framework of the density functional theory within the generalized gradient approximation. The thermophysical properties for temperatures up to 600 K are determined and analyzed in detail using the quasi-harmonic Debye model. Experimentally, the beta-PbO2 transforms to alpha-PbO2 at around 1 GPa. For that, the maximum value of pressure considered here is taken to be 1 GPa. Our findings show that the thermophysical properties of interest vary monotonically with both temperature and pressure which is consistent with previous studies of semiconducting materials. At zero pressure and temperature of 300 K, the isothermal bulk modulus and the Debye temperature are found to be around 113 GPa and 370.5 K, respectively.