Evolution of electromechanical properties in Fe-doped (Pb,Sr)(Zr,Ti)O3 piezoceramics

Chuan Chen,Wen Gong,Qing Tan,Fang-Zhou Yao,Ke Wang,Yan Wang,Chun Liu,Zong-Yue Li,Bing Han

doi:10.1007/s40145-021-0460-7

Abstract

Defects in acceptor-doped perovskite piezoelectric materials have a significant impact on their electrical properties. Herein, the defect mediated evolution of piezoelectric and ferroelectric properties of Fe-doped (Pb,Sr)(Zr,Ti)O3 (PSZT-Fe) piezoceramics with different treatments, including quenching, aging, de-aging, and poling, was investigated systematically. Oxygen vacancies with a cubic symmetry are preserved in the quenched PSZT-Fe ceramics, rendering them robust ferroelectric behaviors. In the aged PSZT-Fe polycrystals, defect dipole between Fe dopant and oxygen vacancy has the same orientation with spontaneous polarization PS, which enables the reversible domain switching and hence leads to the emergence of pinched polarization hysteresis and recoverable strain effect. And the defect dipoles can be gradually disrupted by bipolar electric field cycling, once again endowing the aged materials with representative ferroelectric properties. For the poled PSZT-Fe polycrystals, the defect dipoles are reoriented to be parallel to the applied poling field, and an internal bias field aligning along the same direction emerges simultaneously, being responsible for asymmetric hysteresis loops.

Highlights

Piezoelectric materials with the ability to directly convert mechanical energy into electrical energy, and vice versa, have found themselves applied in enormous pivotal devices, such as robust fuel injectors, ultrasonic medical diagnostic apparatuses, delicate positioning systems, etc. [1,2,3,4,5,6]
Representative PSZT–Fe lead-containing piezoelectric ceramics are the materials of choice
The X-ray diffraction (XRD) pattern of PSZT–Fe sample is shown in Fig. 1(a), indicating that the material has a pure perovskite structure

Summary

Introduction

Piezoelectric materials with the ability to directly convert mechanical energy into electrical energy, and vice versa, have found themselves applied in enormous pivotal devices, such as robust fuel injectors, ultrasonic medical diagnostic apparatuses, delicate positioning systems, etc. [1,2,3,4,5,6]. In the former scenario, the charge carrier agglomeration at domain walls or internal barriers would result in the built-up of an internal bias field; whereas in the latter case, defect dipoles re-orient with respect to the spontaneous polarization and by that imprint a preferred orientation It is not clear how much these different mechanisms contribute to the overall aging mechanism and which dominate in the different materials. The evolution of electromechanical properties, including the large signal properties polarization P3 and strain S3 as well as the small signal parameters piezoelectric coefficient d33 and permittivity ε33 for Fe-doped (Pb,Sr)(Zr,Ti)O3 polycrystals with different treatments, namely quenching, poling, aging, and de-aging, are systematically studied All these features and their origins are discussed in the context of defect dipole formed between Fe dopant and oxygen vacancy

Experimental

Results and discussion

Conclusions