Polarization- and Strain-Mediated Control of Negative Thermal Expansion and Ferroelasticity in BiInO3–BiZn1/2Ti1/2O3

A solid solution between polar perovskite oxides BiInO3 and BiZn1/2Ti1/2O3 with the atomic displacement of Bi3+ and B-site (In and Zn1/2Ti1/2) as the origin of spontaneous electric polarization was investigated. Polar orthorhombic to nonpolar orthorhombic transition accompanied by negative thermal expansion (NTE) with constant volume shrinkage was observed for x ≤ 0.3 in BiIn1–xZnx/2Tix/2O3. A relative shift of electrical polarization from A-site Bi3+ to B-site ions reduced the transition temperature and enabled NTE in a wide temperature range with suppressed temperature hysteresis. In addition, new LiNbO3-type phases were found for 0.4 ≤ x ≤ 0.8 with ferroelastic and piezoelectric behaviors, featuring a very high switching strain and demonstrating the potential for enhanced domain wall mobility.