Preparation of Ba2NaNb5O15 thin films by the sol-gel method

Ba2NaNb5O15 thin films were prepared on Pt and quartz substrates by the sol-gel method using Ba (CH3COO)(2), NaNO3 and Nb (O-n-Bu)(5). Very smooth surface films with a single phase of Ba2NaNb5O15 were obtained by heat treatment at 800 degrees C for 1 h. The remanent polarization and coercive field estimated from the ferroelectric hysteresis loop were 3.5 mu C/cm(2) and 21.6 kV/cm, respectively. The dielectric constant and tan delta at room temperature were 176 and 0.03, respectively. The thin films on quartz substrates mere optically transparent in the visible to ultraviolet region. It is expected that Ba2NaNb5O15 thin films will be applied to ferroelectric memories and optoelectronic devices.