A Structural Study of the Amorphous to Crystalline Transformation in In 2 O 3 Thin Films

We have investigated the structure of sputter deposited amorphous and crystalline indium oxide films by electron diffraction. Selected area diffraction patterns were recorded for both states from which radial density functions were derived. The comparison of the crystalline radial density function to the amorphous one shows that the first nearest neighbor distance corresponding to the In-O bond length is 2.2A and is the same for both states. A model density function for crystalline structure was used to explore the difference in higher order peak positions. We report that the In-In separation in amorphous state has a single characteristic distance of 3.6A compared to the crystalline state which has two non-equivalent In sites and consequently different separations as In(1)-In(2) at 3.4A and In(2)-In(2) at 4.3A.