Dielectric properties of Na0.25K0.25Bi0.5TiO3lead-free ceramics

✍ Scribed by Zhao, Suchuan ;Zhang, Lina ;Li, Guorong ;Wang, Tianbao ;Ding, Aili

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 188 KB
• Volume: 202
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200409092

✦ Synopsis

Abstract

Na~0.25~K~0.25~Bi~0.5~TiO~3~ (NKBT50) lead‐free ceramics were prepared by solid‐state reaction. The dielectric property of the ceramics was investigated from room temperature to 400 °C. There exists a dielectric anomaly between room temperature and 150 °C for the unpoled ceramics sintered in air atmosphere while the anomaly disappears after the ceramic were poled or sintered in oxygen. It is believed that the dielectric anomaly is caused by defect dipoles related to oxygen vacancies due to the volatility of the bismuth component and the effect of poling to it is discussed. The materials undergo a ferroelectric‐antiferroelectric phase transition at 225 °C and the dielectric anomaly corresponding to this phase transition also is affected by oxygen vacancies. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)