Understanding the reason for large dielectric response in Pb-free (1-x)Ba(Zr 0.2 Ti 0.8 )O 3 -x(Ba 0.7 Ca 0.3 )TiO 3 f erroelectric ceramics

Understanding the reason for large dielectric response in Pb-free (1-x)Ba(Zr_0.2Ti_0.8)O₃-x(Ba_0.7Ca_0.3)TiO_{3 f}erroelectric ceramics

Jinghui Gao ¹, Xinghao Hu ¹, Yan Wang ¹, Yongbin Liu ¹, Xiaobing Ren ²

¹ State Key Laboratory of Electrical Insulation and Power Equipment and Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, Xi’an Jiaotong University, Xi'an, China
² Ferroic Physics Group, National Institute for Materials Science, Tsukuba, Japan

(1-x)Ba(Zr_0.2Ti_0.8)O₃-x(Ba_0.7Ca_0.3)TiO₃ (BZT-xBCT) ceramics have been reported to exhibit large dielectric response in the vicinity of the multi-phase-coexisting point (i.e. triple point). However, the reason for large dielectric response in such a material system is still unclear and thus awaits explanation. In this paper, we investigate the reason for large dielectric response by studying the phase transition behavior around the triple point of BZT-xBCT ceramics. Rayleigh analysis indicates that strong dielectric response is due to large reversible contribution caused by phase transition. Moreover, TEM study shows a mottled domain structure with numerous nanodomains close to triple point. Further thermal analysis results suggest that the enthalpy nearly vanishes and the associated specific heat shows discontinuity on the triple point, which suggest a nearly tricritical behavior, which maybe responsible for large dielectric permittivity in BZT-xBCT.

Reference:

Tu-S13-O-04

Presenter/s:

Jinghui Gao

Presentation type:

Oral communication

Room:

Room2

Chair/s:

Wei Ren

Date:

Tuesday, September 5th, 2017

Time:

12:00 - 12:15

Session times:

11:15 - 12:30

IMF2017