Impedance spectroscopy analysis for high-Tc BaTiO3-(Bi1/2Na1/2)TiO3 lead-free PTCR ceramics

✍ Scribed by Leng, Senlin ;Zheng, Liaoying ;Li, Guorong ;Zeng, Jiangtao ;Yin, Qingrui ;Xu, Zhijun ;Chu, Ruiqing

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 768 KB
• Volume: 208
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.201000061

✦ Synopsis

Abstract

The ac impedance measurement was used to investigate the yttrium (Y)‐doped 0.99BaTiO~3~‐0.01Bi~1/2~Na~1/2~TiO~3~ (0.99BT‐0.01BNT) lead‐free positive temperature coefficient of resistivity (PTCR) ceramics in the frequency range from 40 Hz to 2 MHz and in the temperature range from room temperature to 240 °C. The resistivity and capacitance of each electrical component can be obtained from the complex impedance and electric modulus spectroscopy. These obtained data were discussed and compared with directly experimental measured results. In addition, the surface acceptor‐state density and depletion layer thickness were calculated. The grain‐boundary potential barrier of the samples was also estimated according to the Heywang model, the value was between 0.17 and 0.55 eV in the temperature range of 150–240 °C.