%0 Journal Article
%T Effects of LaFeO3 Additions on the Dielectric and Ferroelectric Properties of (K0.5Na0.5)NbO3 Ceramics
%A CHENG Hua-Lei
%A DU Hong-Liang
%A ZHOU Wan-Cheng
%A LUO Fa
%A ZHU Dong-Mei
%J 无机材料学报
%D 2012
%I Science Press
%R 10.3724/sp.j.1077.2012.12325
%X Pure (K0.5Na0.5)NbO3 and 0.98(K0.5Na0.5)NbO3-0.02LaFeO3 ceramics (abbreviated as KNN and 0.98KNN-0.02LF, respectively) were prepared by a solid state reaction approach, and their crystal structure, dielectric and ferroelectric properties were investigated. Pure KNN and 0.98KNN-0.02LF ceramics are the orthorhombic structure and pseudo-cubic perovskite structure, respectively. Dielectric measurements revealed that the dielectric permittivity curves of 0.98KNN-0.02LF ceramics present two anomalies compared with pure KNN: (i) The orthorhombic- tetragonal transition (TO-T) and the tetragonal-cubic transition (TT-C) shifts to lower temperatures. (ii) The phase transition temperature range around the temperature of the maximum dielectric permittivity (Tm) becomes more and more broad. In addition, 0.98KNN-0.02LF ceramics exhibited a very stable temperature dependence of dielectric permittivity with permittivity maximum near 2000 and dielectric loss less than 4% in the temperature range of 0–400  The relaxation behavior of the 0.98KNN-0.02LF ceramics is interpreted in terms of polar nanoregions (PNRs) caused by cations disorder. The P-E hysteresis loops further confirms the relaxor behavior in 0.98KNN-0.02LF ceramics.
%K <p>(K0.5Na0.5)NbO3
%K dielectric properties
%K ferroelectric properties
%K relaxor properties
%K lead-free ceramics</p>
%U http://www.jim.org.cn/fileup/PDF/20121118.pdf