STRUCTURAL, OPTICAL, AND DIELECTRIC-PROPERTIES OF SOL-GEL DERIVED SRTIO3 THIN-FILMS

Transparent and crackfree SrTiO3 thin films were deposited on silicon wafers, fused silica, and stainless-steel substrates by sol-gel techni que. Strontium ethyl hexanoate and titanium isopropoxide were used as starting materials. The surface topology of the films were studied by electron micrography and the structural properties by x-ray diffractio n. The refractive index and band gap were measured by optical transmis sion and absorption spectroscopy. The films show very low leakage curr ent and nearly temperature independent dielectric constant at high fre quencies. The dielectric constant and loss factor at 1 kHz at room tem perature were 131 and 0.022, respectively. The frequency dependent ac conductivity has been explained on the basis of potential barriers for med by the charge carriers trapped at intercrystalline regions.