Rosita Persoons

Composition-crystallinity-property relations in Mg-M-O films

The crystallographic properties such as texture and the level of crystallinity are important issues for the application of thin films. A fundamental understanding of the thin film growth mechanism forms the key to tune these properties. To understand the transition from crystalline-to-amorphous noticed when changing the composition of oxide thin films, Mg-M-O thin films (with M = Al, Cr, Ti, Zr, and Y) were deposited using reactive magnetron sputtering. Because substituting Mg by M yields to vacancy formation, the observed transition can be compared to the crystalline-to-liquid transition noticed in the hard sphere model, when the packing density is changed. The hardness and the bang gap of the Mg-M-O were measured. Using the packing density, it is possible to decouple the influence of the crystallinity from the influence of the composition in the hardness and band gap of the thin films.