化学溶液法制备PbZr_(0.5)Ti_(0.5)O_3/La_(0.5)Sr_(0.5)CoO_3铁电多层薄膜的结构和光学性质研究

STRUCTUREAL AND OPTICAL PROPERTIES OF PbZr_(0.5)Ti_(0.5) O_3/La_(0.5)Sr_(0.5)CoO_3 MULTILAYER THIN FILMS PREPARED BY CHEMICAL SOLUTION ROUTES

采用金属有机化学液相沉积法在Si衬底上制备了La0 .5Sr0 .5CoO3(LSCO)导电金属氧化物薄膜 ,采用溶胶 凝胶法在LSCO导电金属氧化物薄膜上沉积了PbZr0 .5Ti0 .5O3(PZT)铁电薄膜 .X 射线测量结果表明在 70 0℃的退火温度下制备的PZT/LSCO铁电多层薄膜呈 (110 )取向的钙钛矿结构 ,谢乐公式估算铁电薄膜的晶粒尺寸为 5 0～ 80nm .原子力显微镜观察结果显示 :薄膜表面平整 ,均方根粗糙度 (RMS)小于 5nm .用拉曼光谱测量表明PZT薄膜呈拉曼活性 .椭圆偏振光谱仪用来表征薄膜在 40 0～ 170 0nm波长范围的光学性质 .用洛仑兹模型来描述PZT和LSCO薄膜的光学性质 .获得PZT和LSCO薄膜的折射率、消光系数等光学常数谱 .

La0.5Sr0.5CoO3 (LSCO) thin films were deposited on Si substrate by metalorganic chemical liquid deposition (MOCLD). PbZr0.5Ti0.5O3 (PZT) were deposited on LSCO thin films by sol-gel process. X-ray diffraction investigation shows that PZT/LSCO multilayer thin films are polycrystalline with preperential (110) -orientation and contain perovskite phase only. The grain diameter of PZT was estimated to be about 50 similar to 80 nm by Scherrer's equation. Atomic force microscopy measurement shows that the films have smooth surface with RMS < 5 nm. Raman spectrum was used to study the structural property of PZT/LSCO thin films. The optical properties of the films were measured by spectroscopic ellipsometry in the wavelength range of 400 &SIM; 1700nm. Lorentz model was used to express the optical properties of PZT and LSCO thin films. Optical constants (refractive index n and extinction coefficient k) of the PZT and LSCO films were obtained.