溶胶-凝胶法制备外延Ba1-xSrxTiO3薄膜及其结构与性能研究

应用溶胶-凝胶技术在Pt/MgO(100)衬底上成功地制备了Ba0.65Sr0.35TiO3外延薄膜.XRD和SEM分析结果表明该薄膜在O2气氛中650℃热处理1h后,其(001)面是沿着Pt(100)和MgO(100)面外延取向生长的;薄膜表面均匀致密,厚度为260nm,平均晶粒大小为48.5nm.当测试频率为10kHz时,BST薄膜的介电常数和损耗因子分别为480和0.02.介电常数-温度关系测试结果表明sol-gel工艺制备的Ba0.65Sr0.35TiO3薄膜其居里温度在35℃左右,且在该温度下Ba0.65Sr0.35TiO3薄膜存在扩散铁电相变特征.当外加偏置电压为3V时,BST薄膜的漏电流密度为1.5×10-7A/cm2.该薄膜可作为制备新型非制冷红外焦平面阵列和先进非制冷红外热像仪的优选材料.

EPITAXIALLY GROWN Ba1-xSrxTiO3 THIN FILMS BY SOL-GEL TECHNIQUES AND ITS STRUCTURE AND PROPERTIES

Epitaxial Ba 0.65 Sr 0.35 TiO 3 thin films were successfully deposited on Pt?MgO(100) substrates by sol gel techniques. XRD patterns demonstrated that(001) planes of BST films were mainly oriented parallel to Pt(100) and MgO(100). SEM results showed that the surface of BST thin film was smooth and free of cracks, and the film thickness was 260nm. The average grain size of the films was about 48.5nm. The dielectric constant and dissipation factor for Ba 0.65 Sr 0.35 TiO 3 thin film at a frequency of 10kHz were 480 and 0.02, respectively. The temperature dependence of dielectric constant exhibited sharp Curie transitions at temperatures around 35℃. The leakage current density of a BST film on Pt?MgO was 1.5×10 -7 A?cm 2 at an applied voltage of 3V. Such epitaxial Ba 0.65 Sr 0.35 TiO 3 thin films are the excellent materials for preparing uncooled infrared focal plane arrays.