Giant Dielectric Behavior and Complex Impedance of Cu²⁺ Doped Ba_0.9Ca_0.1Ti_0.9Zr_0.1O₃ Ceramics Prepared by Hydrothermal Method

Abstract

Ceramics in the solid solution system, Ba_0.9Ca_0.1Ti_0.9Zr_0.1O₃-xCu²⁺ (BCTZ-Cu²⁺) were prepared by hydrothermal method assisted by microwave sintering. Single orthorhombic phase perovskite-type X-ray diffraction patterns were observed for all doped ceramics, while the addition of Cu²⁺ had no significant effects on the microstructure of BCTZ-Cu²⁺ ceramics. Dielectric measurements indicated a significant increase in dielectric constant and a slight increase in Curie Temperature (T_C) with increasing x, and the Maxwell-Wagner effects can be detected at lower x. The impedance complex plane plots of sample for x=0.16 turned into one semicircular arc at 200°C from a single line at 100°C and then to two semicircular arcs at 300°C and 400°C, which can be analyzed as four different equivalent circuits. Both the R_g and R_e measured at 400°C decreased with increasing x.

Keywords:

• BCTZ
• dielectrics
• electrical properties
• electroceramics

Funding

This research was supported by the National Natural Science Foundation of China (51372144), the New Century Excellent Talents Program of Chinese Education Ministry (NCET-11-1042), the Key Program of Innovative Research Team of Shaanxi Province (2014KCT-06) and the International Science and Technology Cooperation Project Funding of Shaanxi Province (2012KW-06).