EFFECTS OF TEMPERATURE AND ION-TO-ATOM RATIO ON THE ORIENTATION OF IBAD MOS2 COATINGS

MoS2 coatings, 55-800 nm thick, were grown by ion-beam-assisted deposition (IBAD) using different ion-to-atom ratios and deposition temperatures. Crystallinity and orientation of the IBAD MoS2 coatings were determined by X-ray diffraction (XRD). Only XRD peaks corresponding to (001), (hkO), and amorphous MoS2, and a previously unreported low-2 Theta peak (2 Theta approximate to 10.7 degrees) were observed. The basal (002) peak intensities varied primarily with ion-to-atom ratio; the greatest basal intensity occurred when the ion-to-atom ratio produced about 1 displacement per atom. Although a secondary factor in basal intensity, deposition temperature was the primary factor in edge (100) intensity. Edge intensity increased with increasing temperature; it appears that the increases are due to annealing of randomly-oriented MoS2, which converts to edge orientation. The origin of the low-2 Theta peak is unknown, but appears to be associated with the basal planes of MoS2.