| Lead Lanthanum Zirconate Titanate (PLZT) and Strontium Barium Titanate (BST) thin films are excellent materials for the potential applications in optical waveguide and optical commutation, due to their excellent electrical, optical and electro-optical (E-O) properties.Composition of PLZT target, preparation of PLZT and BST thin films, effects of annealing temperature and substrates on optical properties, band gap and residual stresses were investigated. The following are a series of results:PLZT(8/65/35) ceramic sintered at 1100℃and excess 2mol% Pb3O4 is an ideal target composition for ferroelectricity and perovskite structure. The remanent polarization and coercive field are 30μC/cm2 and 9 kV/cm, respectively. Curie temperature is about 150℃.Residual stresses of BST thin films are tensile stresses, grain size and stresses increase with annealing temperature. The difference on composition between ceramics and thin films is very little, (Ba+Sr)/ Ti>1.PLZT thin films were prepared on quartz substrate by RF-magnetron sputtering and then sintered at 550℃,580℃,620℃and 650℃, respectively. Reflective index n and extinction coefficient k increase with growth temperature, transmittance is about 80% in the wavelength of 450-800 nm. The band gap Eg are 3.62 eV, 3.58 eV, 3.55 eV and 3.51eV corresponding to 550℃,580℃,620℃and 650℃. |
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