Ceramics-Silikáty 49 (1) 7-12 (2005)

Crystallization Behavior and Phase Relations of H-MOD Derived Thin Films Based on Barium Sodium Niobates

J. Lou, H. Y. Lee, J.-H. Lee, J.-J. Kim, S.-H. Cho

Ba₂NaNb₅O₁₅, hereafter called BNN, thin film is an attractive candidate for such applications as nonvolatile memory and electro-optic devices. BNN thin films of about 450nm thickness that have different contents of Ba, Na and Nb have been prepared by hybrid metalorganic decomposition, hereafter called H-MOD, process using bare and platinized Si wafers as substrate. XRD and FE-SEM measurements were used to investigate the phase evolution behavior and the microstructure of the films. It was found that Nb content strongly influenced the phase formation of the films, where BaNb₂O₆ phase was always formed at the stoichiometric BNN composition. However, the amount of BaNb₂O₆ phase decreased with the increase of excess Nb content, and the thin film with single phase orthorhombic tungsten bronze structure was obtained at the temperature as low as 750°C.

Keywords: Tungsten bronze structure, BNN, Ferroelectric thin film, H-MOD