Characteristics of TIB2 films prepared by ion beam sputtering

TiB2 films have been prepared by ion beam sputtering. Substrate temperature ranged from ambient temperature (50 degrees C) to 480 degrees C. Atomic force microscopy, X-ray photoelectron spectroscopy, X-ray diffraction and an ultramicroindentation system were used to characterize the deposited films. It was found that films deposited at both ambient temperature and elevated temperature are smooth and have the same B:Ti ratio of 1.8. The films deposited at ambient temperature are amorphous, whereas films deposited at 480 degrees C are principally crystalline TiB2 with a hexagonal structure. The crystallized TiB2 films exhibit a strong (101) preferred orientation. In addition, the lattice parameter of the deposited films decreases with increasing substrate temperature. The ultramicroindentation tests showed that the hardness of the deposited films increases with increasing substrate temperature. The crystalline TiB2 films deposited at 480 degrees C have a very high microhardness of about 48 GPa, equivalent to 4400 kgf mm(-2) Vickers hardness.