A water-soluble precursor of BaTiO3 and transparent BaTiO3 thin-films prepared from the solution by a water-based dip-coating technique

作者：Iwase Katsuhiko; Kasuga Shinnosuke; Kawai Takahiro; Matsushima Yuta^*

来源：Journal of Sol-Gel Science and Technology, 2012, 64(1): 170-177.

DOI：10.1007/s10971-012-2844-1

• Sol-gel processes
• Films
• Optical properties
• BaTiO3
• Water soluble precursor

A new water-soluble precursor of BaTiO3 was prepared from citratoperoxotitanate and barium citrate as the Ti and Ba sources, respectively. The water-soluble precursor was easily solved in water to form a stable solution, which produced BaTiO3 by heat-treatment at 500 A degrees C and above. A water-based dip-coating technique demonstrated a potential application as the coating solution of BaTiO3. Transparent BaTiO3 films were formed on the quartz-glass substrates with an increment of typically 9 nm per coating with 0.05 mol dm(-3) solution. The transmittance of the 180 nm-thick film attained almost 90 % at the maximum and the overall transmittance was above 60 % over the visible region. The polycrystalline film was composed of BaTiO3 grains smaller than 200 nm. Although the film was an insulator, it was not suited for the dielectric application because of the structural problems due to the relatively low density and the thinness of the BaTiO3 layer. The BaTiO3 pellet obtained from the water soluble precursor by condensation, pyrolysis and sintering showed the good dielectric properties with epsilon(r) = 3,500 and tan delta = 0.027 with a sintering temperature of 1,375 A degrees C.

• 出版日期2012-10