Equivalence of physical pressure and chemical pressure in the phase transformation of undiscovered Sb<i>x</i>Bi(1−<i>x</i>)ScO3 compound

A new approach based on a Clausius–Clapeyron-like equation was previously proposed to evaluate the equivalence of physical transformation pressure and chemical pressure and to search for new phase transformations of B-site doping BiScO3-based compounds, which have potential for high-temperature piezoelectric materials [J. Appl. Phys. 137, 135105 (2025)]. Here, this computational route, which combines density functional theory and thermodynamics, was successfully applied to evaluate the phase transformations of A-site doping BiScO3-based compounds SbxBi(1−x)ScO3 (x = 0–1). Compared to B-site doping, the A-site doping Sb0.5Bi0.5ScO3 compound exhibited a richer variety of phase transformations up to 12 types. The phases of SbxBi(1−x)ScO3 preferred to transform toward the R3 phase, whereas transformations towardsthe R1 phase were more prevalent in BiRxSc(1−x)O3 compounds. The difference between A-site and B-site doping BiScO3 compounds was further discussed via the estimation of doping concentration using the direct first-principles calculations route. The quantitative prediction of phase transformation induced by doping BiScO3 compounds has been completely established through the calculation of the A-site phase transformation diagram, which serves as a map to guide the experimental design of BiScO3-based high-temperature piezoelectric materials.