水溶液反応場におけるセラミック薄膜プロセッシング

Abstract

This article reviews the techniques of the deposition of ceramic thin films from aqueous solutions and the development of the water-based starting solution for the dip-coating deposition of ceramic thin films. As a solid-precipitation reaction proceeds at an appropriate rate in an aqueous solution in contact with a substrate, heterogeneous nucleation takes place followed by crystal growth to form a ceramic thin film. The precipitation reaction is designed depending on the kind of the metal ion comprised in the ceramic film. In the present article, the following advantages unique to the aqueous solution-based thin film deposition are outlined. It is easy to scale-up the film deposition process, and the film thickness is homogeneous throughout the film. The nano-scale microstructure can be imprinted by using surfactant templates which should extend the application of the films. Calcium phosphate thin films deposited with the mediation of an enzyme were found to promote bone formation by in vivo tests. A homogeneous precursor solution of barium titanate was prepared. The solution may be advantageous over conventional alkoxide-based solutions or sol suspensions in terms of long-term stability and precise composition control.