Structural phase transition, optical and pyroelectric properties of lead-free single crystals

Abstract

0.14 at% Mn-doped 0.95(Na 1/2 Bi 1/2 )TiO 3 -0.05BaTiO 3 (0.95NBT-0.05BT) lead-free single crystals were grown by a top-seeded solution growth method (TSSG). X-ray powder diffraction measurement showed that the as-grown single crystals exhibit rhombohedral perovskite structure with apparent distortion. With the increase of temperature, successive structural phase transitions occur in the Mn-doped 0.95NBT-0.05BT single crystals. After poling, apparent dielectric anomaly is induced accompanied by the increase of the character of diffuse phase transition and the decrease of the value of dielectric constant. The Mn-doped 0.95NBT-0.05BT single crystals exhibit complex domain structure, in which micro and macro domains coexist with statistically 4 mm symmetry. The Mn-doped 0.95NBT-0.05BT lead-free single crystals exhibit excellent piezoelectric and pyroelectric properties, which will lead to promising advance in piezoelectric and pyroelectric applications. The infrared-absorption band occurred around 630.6 cm 1 can be assigned to the "stretching" normal vibration of [Na With the demand for sustainable development of environmental protection and human society, development of lead-free piezoelectric materials that can replace hazardous lead-based Pb(Zr x Ti 1x )O 3 (PZT) piezoelectric ceramics has been research hot in piezoelectric application fields [1][2][3]. Among lead-free piezoelectric materials, (1x)(Na 1/2 Bi 1/2 ) TiO 3 -xBaTiO 3 (NBT-BT) solid solutions attract great research attention due to their excellent piezoelectric performance [4,5]. Since piezoelectric materials existence in crystallographically engineered single crystals exhibit more excellent piezoelectric properties, much work has been undertaken on the growth of high-quality and large-size NBT-BT single crystals [6,7].From the viewpoint of crystal chemistry, the extraordinarily enhanced piezoelectric properties of solid solution ferroelectrics are considered as correlating with the engineered ferroelectric domain configuration, the relaxor nature of the compositions around the morphotrophic phase boundary (MPB), and the polarization rotation via intermediate monoclinic or orthorhombic states [8][9][10]. As for the NBT-BT system, Takenaka et al. [4] determined its MPB composition locating at x=0. 06-0.07, in which the NBT-BT single crystals with the compositions around the MPB exhibited large electric field-induced strain and excellent piezoelectric property [11]. However, the contributions of engineered domain structure, relaxor behavior nature and polarization rotation path on the MPB effects should be given more fundamental research.

Aging Behavior and Mechanical Properties of 0.69Pb(Mg1/3Nb2/3)O3-0.31PbTiO3Ceramics

“…Piezoelectric properties and their influences by environmental temperature were measured by a ZJ-6A Berlincourt-type quasi-static d 33 /d 31 meter (Institute of Acoustics, Chinese Academy of Sciences, Beijing, China) and a TH2826 Wide Frequency LCR Meter (Changzhou Tonghui Electronic Co. Ltd., China) using the resonance-antiresonance method. Detailed electrical properties measurement procedures were described elsewhere [15].…”