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Dielectric Relaxor of A Site Complex Ferroelectric Ceramics of

Author(s): ZHOU Chang-Rong,LIU Xin-Yu,YANG Gui-Hua,JIANG Min-Hong

Journal: Journal of Inorganic Materials
ISSN 1000-324X

Volume: 24;
Issue: 5;
Start page: 953;
Date: 2009;
Original page

Keywords: sodium bismuth titanate | ferroelectric ceramics | dielectrics properties | relaxor characteristics

A new A site complex lead-free ferroelectric ceramics of (1-x)Bi0.5(Na0.82K0.18)0.5TiO3-xBiCrO3(BNKT-BCx) was prepared by a conventional solid state reaction method and dielectric properties of the system in the temperature from room temperature to 500¡䟷ere investigated. It can be evidently seen that there are two abnormal dielectric peaks and a dielectric loss peak with increasing temperature. The dielectric constant near temperature of low abnormal peak has obvious frequency dependence, and Curie temperature shifts insignificantly with increasing frequency, which is different from the characteristics of typical relaxor ferroelectrics. It suggests that relaxor ferroelectrics can be divided into the intrinsic relaxor ferroelectrics and extrinsic relaxor ferroelectrics. The frequency dependence near the temperature of low dielectric peak is extrinsic relaxor which is created by space charges and defects dipole by using the ¦ü/EM>r-T curves of poled and unpoled samples.