Recommendations for the fabrication of thin, clean and uniform films of materials of high evaporation temperatures at low pressures are presented. The convenience of the use of electron bombarded source techniques focus, precautions to avoid overheating and the necessity of excellent cleaning are stressed. Contamination by higher vapor pressure substances and other known difficulties associated with the handling of materials at high temperatures were minimized. Good quality films of Zr, Mo and Ru, for use in nuclear physics experiments, were obtained.
