Microwave dielectric properties and crystal structures of 0.7CaTiO₃-0.3[La_xNd_(1?x)]AlO₃ ceramics

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• 作者：Fei Liang ; ^{liangfei@mail.hust.edu.cn} ; Meng Ni ; Wenzhong Lu ; Guifen Fan
• 关键词：0.7CaTiO3&ndash ; 0.3[LaxNd(1&minus ; x)]AlO3 ; Microwave dielectric properties ; Crystal structure
• 刊名：Journal of Alloys and Compounds
• 出版年：2013
• 出版时间：15 August, 2013
• 年：2013
• 卷：568
• 期：Complete
• 页码：11-15
• 全文大小：1374 K

文摘

The microwave dielectric and sintering properties of 0.7CaTiO₃-0.3[La_xNd_(1?x)]AlO₃ (CTLNA) specimens have been investigated in this work. It has been found that microwave dielectric properties and crystal structures depend on the LaAlO₃ content. When x < 0.5, the crystal structure of 0.7CaTiO₃-0.3[La_xNd_(1?x)]AlO₃ was tetragonal and it changed to the orthorhombic structure when x ? 0.5. When x = 0.5, specimens exhibited excellent microwave dielectric properties with ¦Å_r = 46.51, Q ¡Á f = 39,928 GHz (@3.8 GHz), ¦Ó_f = + 10 ppm/¡ãC. In order to further improve the microwave dielectric properties of the samples, Ca²⁺ in 0.7CaTiO₃-0.3[La_xNd_(1?x)]AlO₃ were partially substituted by Sr²⁺. The results showed that the addition of SrTiO₃ inhibited the growth of the crystal grain and improved the densification of specimens. By optimizing the composition and preparation process, CTLNA specimens with ¦Ä = 0.01 in 0.7[Sr_¦ÄCa_(1?¦Ä)]TiO₃-0.3[La_0.5Nd_0.5]AlO₃ (SCTLNA) showed high density and a uniform grain structure with ¦Å_r = 45.87, Q ¡Á f = 41612 GHz (@4 GHz), ¦Ó_f = + 10 ppm/¡ãC.