Novel high-temperature-resistant material SbLaO₃ with superior hardness under high pressure

Perovskites have garnered significant attention in recent years. However, the presence of La atoms at the B-site in ABX₃ structures has not yet been observed. Under high pressure, perovskites exhibit unexpected phase transitions. In this study, we report the discovery of SbLaO₃ under ambient pressure, with a space group of R3m. Mechanical property calculations indicate that it is a brittle material, and it possesses a band gap of 4.0266 eV, classifying it as an insulator. We also investigate the phase at 300 GPa, where the space group shifts to P2₁/m. Additionally, the P2₁/m phase of LaInO₃ under 300 GPa is explored. Ab initio molecular dynamics calculations reveal that the melting point of SbLaO₃ is exceptionally high. The inclusion of Sb alters the electronic structure compared with LaInO₃, and the Vickers hardness (H_v) is estimated to reach 20.97 GPa. This research provides insights into the phase transitions of perovskites under high pressure.