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

Abstract Perovskites have garnered significant attention in recent years. However, the presence of lanthanum atoms at the B-site in ABX$_3$ structures has not yet been observed. Under high pressure, perovskites exhibit unexpected phase transitions. In this study, we report the discovery of SbLaO$_3$ under ambient pressure, with a space group of $R$3$m$. 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 investigated the phase at 300 GPa, where the space group shifts to $P$2$_1$/$m$. Additionally, the $P$2$_1$/$m$ phase of LaInO$_3$ under 300 GPa is explored. Ab-initio molecular dynamics calculations reveal that the melting point of SbLaO$_3$ is exceptionally high. The inclusion of antimony alters the electronic structure compared to LaInO$_3$, and the Vickers hardness ($H_v$) is estimated to reach up to 20.97 GPa. This research provides insights into the phase transitions of perovskites under high pressure.