The perovskite structure is commonly observed in diverse functional materials, including ferroelectric ceramics, fuel cell electrodes, and solar cell materials. Originally identified in the mineral calcium titanate (CaTiO₃), from which it derives its name, "perovskite" now broadly encompasses compounds adopting this archetypal structure or its distorted variants. Perovskites follow the general formula ABX₃, where: The A-site is occupied by a larger cation (e.g., alkali metal, alkaline earth metal, rare-earth ion) or bulky atomic group; The B-site hosts a smaller transition metal cation; The X-site is an anion (e.g., halide or chalcogenide ion).

Owing to their compositional flexibility, perovskite materials exhibit rich chemical diversity and numerous derivative structures. Variations in ionic radii can stabilize ideal cubic, tetragonal, orthorhombic, or trigonal symmetries. Their high structural tolerance permits extensive ion substitution at A-, B-, or X-sites and accommodates nonstoichiometry, enabling tailored properties through controlled structural engineering.

Perovskites remain a focal point in both fundamental research and technological applications, with breakthroughs continuously emerging. Similar to temperature and chemical composition, pressure is a pivotal parameter for modulating structure and properties. Under high pressure, reduced interatomic distances intensify interactions, altering crystal and electronic structures to establish novel equilibrium states. High pressure facilitates: Stabilization of dense perovskite phases (e.g., BaRuO₃ synthesized at 18 GPa); Emergence of unusual valence states (e.g., Cu³⁺ in LaCuO₃). Differential compressibility of A–X and B–X bonds induces structural rearrangements under compression, yielding diverse physical phenomena.

To highlight the role of high pressure in synthesizing perovskites and tuning their structures and functionalities, Chinese Journal of High Pressure Physics presents this Special Topic. Contributions explore pressure-driven structural and property evolution in systems including BaMO₃ and PbMO₃ (M = transition metal), NaPO₃, ReO₃, and halide perovskites. We anticipate this topic will engage the high-pressure science community in advancing perovskite research. We extend our gratitude to all contributors and reviewers for their dedication to this Special Topic.

Zhi-Guo Liu

School of Physics, Harbin Institute of Technology