H. Kitahata et al., Preparation and ferroelectric properties of YMnO3 thin films with c-axis preferred orientation by the sol-gel method, J SOL-GEL S, 19(1-3), 2000, pp. 589-593
Hexagonal YMnO3 has a ferroelectric property with an optimal remanent polar
ization along the c-axis. The c-axis oriented YMnO3 thin films with a small
leakage current were prepared by the sol-gel dipping method. The c-axis or
ientation of the films was promoted by the addition of diethanolamine to th
e Mn precursor solution. A heat treatment with multiple steps led to a dens
e film structure with fine grains. The dense structure resulted in the decr
ease of the leakage current. Furthermore, when the films were heat-treated
in a vacuum, the leakage current became considerably small and the ferroele
ctricity of the YMnO3 thin films was observed even at room temperature.