Enhanced electrical properties and conduction mechanism of A-site rare-earth Nd-substituted CaBi2Nb2O9

Affiliation of Author(s):山东大学

Journal:Journal of Physics D: Applied Physics

Abstract:Calcium bismuth niobate (CaBi2Nb2O9, CBN) is considered to be one of the most promising high-temperature (HT) piezoelectric materials owing to its high Curie temperature of similar to 940 degrees C, however, its low electrical resistance and poor piezoelectric properties at elevated temperatures limit its applications at high temperatures. In this work, we report the significantly enhanced dc electrical resistivity and piezoelectric performance of CBN ceramics through rare-earth Nd-substitution. The crystal structure, microstructure, and dielectric, electrical, ferroelectric and piezoelectric properties of Nd-modified CBN with nominal compositions of Ca1-x Nd (x) Bi2Nb2O9 (CBN-100xNd) have been investigated in detail. The results indicate that the substitutions of Nd3+ ions for Ca2+ ions increase the piezoelectric properties, and reduce the dielectric loss tan delta at high temperatures. The dc and ac conduction mechanisms indicate that the conduction mechanism is closely related to oxygen vacancies that are reduced through the donor substitutions of Nd3+ for Ca2+, thereby resulting in a significant improvement in the dc electrical resistivity. The optimal composition of CBN-3Nd exhibits a high piezoelectric constant d (33) of 13.5 pC N-1, and a high Curie temperature T (c) of 948 degrees C. More importantly, the CBN-3Nd exhibits good thermal stability of the electrical properties (rho= 2.6 x 10(7) omega cm at 500 degrees C and 1.8 x 10(6) omega cm at 600 degrees C, k (p) = 6.1%-6.2% at RT similar to 500 degrees C), which demonstrates that the Nd-modified CBN ceramics are promising piezoelectric materials for use in HT piezoelectric sensors.

All the Authors:Qian Wang,Hong-Ting Lu,Xian Zhao

First Author:Juan-Nan Chen

Indexed by:Journal paper

Correspondence Author:Chun-Ming Wang

Discipline:Natural Science

First-Level Discipline:Physics

Volume:55

Issue:31

Page Number:315301

Number of Words:5000

Translation or Not:no

Date of Publication:2022-05-01

Included Journals:SCI

Date of Publication:2022-05-01