Observations on Evaporated Tantalum Films

High purity tantalum was vacuum deposited by electron beam evaporation onto polished {100} surfaces of single crystal MgO heated to temperatures between 700°C and 800°C. An ion pumped vacuum system was used, giving a vacuum of from 3·10 -6 to 5·10 -7 torr during actual deposition. The diffraction pattern from these Ta films (Figure 1) is very similar to that observed by Hutchinson and Olsen for one-quarter hour annealed Nb films.