Piezoelectricity enhancement in Dion-Jacobson RbBiNb2O7 via negative pressure

We use first-principles calculations to study the structural, ferroelectric and piezoelectric properties of the recently synthesized Dion-Jacobson RbBiNb2O7, a novel layered-perovskite piezoelectrics with extremely high Curie temperature T-C. We show that ferroelectric RbBiNb2O7 crystalizes in orthorhombic Pmc2(1) phase, exhibiting in-plane spontaneous polarization. We well reproduce the major experimental results for RbBiNb2O7. We further propose that under 5% volume-expansion-induced negative pressure, similar to 3x increase of dielectric permittivity and similar to 2x increase of piezoelectricity can be achieved in RbBiNb2O7. The decomposed piezoelectricity analysis reveals that the activation of piezoelectric response of cation Rb by negative pressure can lead to large piezoelectricity enhancement. Based on our calculations, we demonstrate that negative pressure is a promising way to optimize the performance of RbBiNb2O7 as high-T-C piezoelectrics. Copyright (C) EPLA, 2014