High‐throughput first‐principle calculations of the structural, mechanical, and electronic properties of cubic XTiO<sub>3</sub> (X = Ca, Sr, Ba, Pb) ceramics under high pressure
Hui Xiao, Touwen Fan, Zhipeng Wang, Te Hu, Xian Tang, Li Ma, Pingying Tang
Abstract
Abstract High‐throughput first‐principle calculations are implemented to study the structural, mechanical, and electronic properties of cubic XTiO 3 (X = Ca, Sr, Ba, Pb) ceramics under high pressure. The effects of applied pressure on physical parameters, such as elastic constants, bulk modulus, Young's modulus, shear modulus, ductile‐brittle transition, elastic anisotropy, Poisson's ratio, and band gap, are investigated. Results indicate that high pressure improves the resistance to bulk, elastic, and shear deformation for XTiO 3 ceramics. Pugh's ratios B / G reveal that CaTiO 3 and PbTiO 3 ceramics are ductile, but SrTiO 3 and BaTiO 3 ceramics are brittle under the ground state. The brittle‐to‐ductile transition pressures are 24.26 GPa for SrTiO 3 and 43.23 GPa for BaTiO 3 . Under high pressure, the strong anisotropy promotes the cross‐slip process of screw dislocations, and then enhances the plasticity of XTiO 3 ceramics. Meanwhile, XTiO 3 (X = Ca, Sr, Ba) is intrinsically an indirect‐gap ceramic, but PbTiO 3 is a direct‐gap ceramic. High pressure increases the band gap of XTiO 3 (X = Ca, Sr, Ba) ceramic, but decreases that of PbTiO 3 ceramic. This work is helpful for designing and applying XTiO 3 ceramics under high pressure.