Room-temperature martensitic actuation profited from one-dimensional hybrid perovskite structure

Abstract Ferroelastic and thermoelastic behaviors are interesting mechanical-related properties usually accompanied by martensitic transformations which can act as mechanical actuation when a stimulus is applied. However, reversible stimuli-response behavior in a crystalline state is rare for molecular crystals because many crystals cannot bear the stress release when the transformation occurs. Here, a new 1D perovskite semiconductor (NMEA)PbI3 (NMEA = N-methylethylamine) was successfully prepared and the crystal undergoes ferroelastic and thermoelastic martensitic transformations showing reversible responsive phenomena. The thermosalient behavior that occurs at the phase transition is very close to room temperature and may have promising applications in mechanical actuators for intelligence devices. This work provides a new approach to designing actuators utilizing weak interactions among chains in 1D perovskites that easily trigger interchain shearing movement.