Phase Evolution and Local Piezoelectric Response of Sn-Doped BaTiO3 Ceramics

Multiphase coexistence is the key to rendering samples with superior piezoelectric properties for BaTiO3 ceramics. Ba(Ti1-xSnx)O-3 (BTS, x = 0.0-0.30) ceramics are prepared by the traditional solid-state method. Orthorhombic (O) and tetragonal (T) phases are visually observed to coexist only in the ceramics with the low-doping of Sn (x = 0.025-0.075) by electron backscattered diffraction (EBSD). The O phase percentage increases from 13.90% to 75.10%, therefore enhancing their piezoelectric response over the decreasing T phase. Further increase of x turns the BTS to rhombohedral (R) and cubic (C) phases, while cathodoluminescence (CL) analysis detects significant redshifts of the defect peak, which is mainly due to the change of phase structure. The phase transition can lead to the change of Ti-O-6 octahedron, thereby affecting the charge transfer between Ti-Ti' andO(o.)(. )High piezoelectric responses can be achieved by the coexistence of O and T phases, which facilitates the rotation of ferroelectric domains. These results are beneficial to understanding the relationship between the microstructure and piezoelectric properties of BTS ceramics, and also indicate that CL can be a useful tool for phase identification.