Ferroelasticity induced by metal substitution in one-dimensional hybrid perovskites†

Ferroelastic materials have attracted significant attention due to their great potential in mechanical switches, piezoelectric sensors, and data storage applications. Hybrid organic–inorganic perovskites (HOIPs) can achieve targeted property control by adjusting organic component, metal center and replacing halogens. By tuning the metal center, we successfully synthesized two one-dimensional HOIPs, (C₃H₅N₂S)SbBr₄ (1) and (C₃H₅N₂S)BiBr₄ (2). The phase transition of 1 is consistent with 2/mF, which is one of the 94 ferroelastic phase transitions derived by Aizu. However, the point group of 2 remains unchanged in both the low-temperature phase and high-temperature phase, meaning 2 does not exhibit ferroelasticity. The difference in metal centers affects the distortion of the octahedron, which plays a key role in determining the space group of the low-temperature phase and ultimately influencing the presence of ferroelasticity. This study demonstrates that metal tuning can effectively modify the ferroelastic properties of materials, offering a new way for designing and synthesizing multifunctional ferroelastic materials.