二氧化钛过渡层对脉冲激光沉积钛酸锶钡薄膜微结构和介电性质的影响  

Effect of TiO_2 anatase layer on the microstructure and dielectric properties of (Ba_(0.6)Sr_(0.4))TiO_3 films prepared by pulsed laser deposition

作　　者：张鹏展[1] 沈明荣[1] 徐俞[1] 

机构地区：[1]苏州大学物理科学与技术学院薄膜材料江苏省重点实验室,苏州215006

出　　处：《功能材料与器件学报》2008年第6期1019-1025,共7页Journal of Functional Materials and Devices

基　　金：国家自然科学基金(No:50576014):旋流式微混合器内旋流流动及相变过程研究

摘　　要：选取极薄TiO2作为过渡层,采用脉冲激光沉积法分别在Si(100)和Pt(111)/Ti/SiO2/Si(100)基底上制备了Ba0.6Sr0.4TiO3(BST)薄膜,研究过渡层对BST薄膜微结构及电学性质的影响。发现厚度20纳米以内的锐钛矿相结晶TiO2过渡层可使BST薄膜由无规则取向转变为(111)择优取向,而非晶和较厚TiO2过渡层对BST薄膜的取向无影响。结晶的TiO2过渡层也使薄膜的表面颗粒变细。还研究了不同厚度TiO2对BST薄膜电学性质的影响,结果表明BST薄膜在Pt(111)底电极上加入极薄的结晶TiO2过渡层后电学性质有明显改善,薄膜的介电常数和可调谐度提高,而介电损耗降低。加入膜厚约5nm的TiO2过渡层后,测试频率为10 kHz时薄膜相应介电常数、介电损耗及可调谐度分别为513、0.053和36.7%。The effect of TiOz buffer layers on the microstructure and dielectric properties of Ba0.6Sr0.4TiO3 （BST） films produced by pulsed -laser deposition technique on both Si （100） and Pt （111 ）/Ti/SiO2/Si （100） substrates was studied. It was found that the microstructure of the films changed from a random orientation to （111） preferred orientation and the grain size was smaller, after inserting the buffer layers. The dielectric properties of BST films deposited on Pt（ 111 ） substrates was found to be dependent on the thickness of the buffer layer. Compared with pure BST films, the dielectric properties of buffered BST films was significantly improved, that the dielectric constant and tunability of BST films were increased while its dielectric loss and dispersion were decreased. At 10 kHz, the dielectric constant, tunability, and the dielectric loss of the BST thin films having about 5 nm TiO2 buffer layer were 513,0. 053, and 36.7%, respectively.

关 键 词：脉冲激光沉积法 BST薄膜 TiO2过渡层 微结构 介电性质 

分 类 号：O484.42[理学—固体物理]