Preparation of Alumina Thin Film with Sponze-like Surface Structure by Sol-Gel Method

Abstract

The alumina thin films with sponze-like surface structure were prepared by the sol-gel method using a 1, 3-butanediol solution of aluminium nitrate. The film usually produced by the spin-coating method and calcined at 500 °C (100 nm thick) has the homogeneous flat surface. However, the additional hot-water treatment at 100 °C for 2 h and calcination at 500 °C changed the surface texture to the sponze-like surface (Fig.3). The film was found to be covered with fibrillay particles of 50-100 nm in length and ca.5 nm in width which were composed of fine -Al₂O₃r particles with the mean size of ca.5 nm (Fig.4). The pores constructed by the aggregate of the fibrillay particles were observed in the range of 100-, 200 nm in diameter by SEM.