Electron Microscopy and Diffraction Studies of the Structure of Amorphous WO₃ Film

Abstract

High-resolution electron-microscopic observation and analysis of the amorphous halos in electron diffraction have been carried out on WO 3 film prepared by vacuum deposition. Crossed fringes forming a region about 1 nm in size are frequently seen in the micrographs, and each of their spacings corresponds to that of the lattice spacing of the WO 3 crystal. On tilting the film, the lattice fringes in some regions disappeared and new fringes appeared at different positions. This shows that the micro-crystallites are distributed at random in the film. The experimental electron diffraction intensity is explained by a micro-crystal model in which microcrystallites are distributed at random with sizes of 0.8, 1.0 and 1.2 nm at ratios of 23, 54 and 23%, respectively.