Y掺杂(Ba_(0.6)Sr_(0.4))_(0.8)TiO_3薄膜的结构及介电性能  

Structure and Dielectric Properties of Yttrium-Doped (Ba_(0.6)Sr_(0.4))_0.8TiO_3 Thin Films by Improved Sol-Gel Method

作　　者：张高俊[1] 廖家轩[1] 李嶷云 徐从玉[1] 王滨[1] 张宝[1] 

机构地区：[1]电子科技大学,四川成都610054

出　　处：《稀有金属材料与工程》2013年第S1期100-102,共3页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51172034);中央高校基本科研业务费专项资金(ZYGX2009X018);电子科技大学中青年学术带头人培养基金(Y02018023601053)

摘　　要：通过钇(Y)掺杂、适当增加钛(Ti)含量和调节薄膜厚度等优化设计,用改善的溶胶-凝胶(Sol-Gel)法制备了光滑致密的Y掺杂多层钛酸锶钡(Ba0.6Sr0.4)0.8TiO3,BST)薄膜,研究了该薄膜的结构及介电性能。X射线衍射(XRD)表明,该薄膜为钙钛矿结构,但其衍射峰强度很弱,主要与Y掺杂和微过量Ti有效减弱其铁电性有关。原子力显微镜(AFM)表明,该薄膜晶化较弱,且随厚度的增加晶化减弱,和XRD结果一致。该薄膜比Y掺杂的Ba0.6Sr0.4TiO3薄膜显示更优异的综合介电性能,但与薄膜的厚度有关。随膜厚的增加,薄膜的电容和调谐率减小,但介电损耗大幅减小,其中,4层薄膜零偏压的介电常数为161、电损耗约为0.006,40V的调谐率为45.5%、优质因子大于75,可满足微波调谐器件的需要。The upgraded Y-doped with concentration of 0.5%/0.6%/0.7%/0.8%/0.9%/1% Ba 0.6 Sr 0.4 TiO 3 thin film and downgraded Y-doped with concentration of 1%/0.9%/0.8%/0.7%/0.6%/0.5% Ba0.6Sr0.4 TiO 3 thin film were prepared on Pt/Ti/SiO2 / Si substrates by an improved sol-gel method. X-ray diffraction shows that all thin films mostly grow along (110) oriented crystal face and are cubic perovskite structure. Graded Y-doped BST thin films exhibit stronger phase-configuration diffraction intensities and crystallization than normal Y-doped BST thin films, and the upgraded Y-doped BST film is the best. Atomic force microscope (AFM) result demonstrates that graded Y-doped BST has better surface morphologies than Y-doped BST. What’s more, upgraded Y-doped film has denser and smoother surface morphologies and smaller roughness than downgraded Y-doped BST film. Voltage-capacitance curves obtained at 40 V and 100 kHz illustrate that upgraded Y-doped BST thin films exhibit markedly improved dielectric properties with capacitance 28.5 pf (permittivity 190) and dielectric loss 1.63% at zero bias, 52.3% tunability at 40 V and merit factor value of 32, meeting the needs of microwave applications.

关 键 词：钇梯度掺杂 钛酸锶钡薄膜 溶胶-凝胶法 介电性能 

分 类 号：O484.1[理学—固体物理]