The growth of epitaxial and wlycrystal KNbO3films via sol-gel process

Transparent and uniform thin films of crystalline KNbO3 were synthesized on different substrates such as SrTiO3, ZrO2 MgO and Pt by the dip-coating method using a double alkoxides solution. The film was epitaxially crystallized at the temperature around 750°C for 3 hours in air on SrTiO3 single crystal substrate. The structure of the films has been studied with X-ray and electron diffraction, and transmission electron microscopy. Different molar ratios of 2-ethylhexanoic acid (ZEHA) to alkoxides were applied to control the hydrolysis rate of the sol-gel solution. Dense films were obtained after modification of the alkoxides solution. P-E hysteresis loop of the film on Pt substrate was also observed.