Ferroelectric and dielectric properties of bismuth-layered structural Sr(2)Bi(4-x)Ln(x)Ti(5)O(18) (Ln = La, Nd, Sm and Dy) ceramics

摘要

La, Nd, Sm, and Dy-doped Sr2Bi4Ti5O18 (SBTi) ceramic samples have been prepared by the solid-state reaction method. The X-ray diffraction reveals that all of the ceramic samples are single phase compounds. Their remnant polarization (2P(r)) increases at first, and then decreases with the increase of doping content. When doping content is 0.01, Sm and Dy-doped SBTi samples exhibit the maximum 2P(r) of 18.2 and 20.1 mu C/cm(2), respectively. While La and Nd-doped SBTi samples display the maximum 2P(r) value of 18.4 and 19.1 mu C/cm(2) with doping content of 0.05 and 0.10, respectively. The ferroelectric properties of Sr(2)Bi(4-x)Ln(x)Ti(5)O(18) are found to be dominated by the competition of the decrease of oxygen vacancy concentration and the relief of structural distortion. (c) 2006 Elsevier Inc. All rights reserved.