Effect of (Ba+Sr)/Ti ratio on dielectric and tunable properties of Ba_(0.6)Sr_(0.4)TiO_3 thin film prepared by sol-gel method  

作　　者：朱伟诚 彭东文 程晋荣 孟中岩 

机构地区：[1]School of Materials Science and Engineering,Shanghai University,Shanghai 200072,China

出　　处：《中国有色金属学会会刊：英文版》2006年第B01期261-265,共5页Transactions of Nonferrous Metals Society of China

基　　金：Project (50332030) supported by the National Natural Science Foundation of China

摘　　要：Ba0.6Sr0.4TiO3 (BST) thin films were fabricated on Pt coated Si (100) substrates by sol-gel techniques with molar ratio of (Ba+Sr) to Ti changing from 0.76 to 1.33. The effect of (Ba+Sr)/Ti ratio deviating from the stoichiometry on microstructure, grain growth, dielectric and tunable properties of BST thin films were investigated. TiO2 and (Ba,Sr)2TiO4 were found as a second phase at the ratios of 0.76 and 1.33, respectively. The variation of the ratio reveals more significant effect on the grain size in B-site rich samples than that in A-site rich samples. The dissipation factor decreases rapidly from 0.1 to 0.01 at 1 MHz with decreasing (Ba+Sr)/Ti ratio. The tunability increases with decreasing ratio from 1.33 to 1.05, and then decreases with decreasing ratio from 1.05 to 0.76. The film with (Ba+Sr)/Ti ratio of 1.05 has a maximum tunability of 32% and a dissipation factor of 0.03 at 1 MHz.Ba0.6Sr0.4TiO3 （BST） thin films were fabricated on Pt coated Si （100） substrates by sol-gel techniques with molar ratio of （Ba＋Sr） to Ti changing from 0.76 to 1.33. The effect of （Ba＋Sr）/Ti ratio deviating from the stoichiometry on microstructure, grain growth, dielectric and tunable properties of BST thin films were investigated. TiO2 and （Ba,Sr）RTiO4 were found as a second phase at the ratios of 0.76 and 1.33, respectively. The variation of the ratio reveals more significant effect on the grain size in B-site rich samples than that in A-site rich samples. The dissipation factor decreases rapidly from 0.1 to 0.01 at 1 MHz with decreasing （Ba＋Sr）/Ti ratio. The tunability increases with decreasing ratio from 1.33 to 1.05, and then decreases with decreasing ratio from 1.05 to 0.76. The film with （Ba＋Sr）/Ti ratio of 1.05 has a maximum tunability of 32% and a dissipation factor of 0.03 at 1 MHz.

关 键 词：Ba0.6Sr0.4TiO3薄膜 溶胶-凝胶法 制备 (钡+锶)/钛配比 介电性质 

分 类 号：TB383.2[一般工业技术—材料科学与工程]