An experimental procedure is described for producing thin films of binary alloys by evaporation and condensation in a vacuum. The components of the desired alloy are evaporated successively and the alloy is then produced by diffusion. A feature of the method is the use of a rotating modulator located between the vapor source and the substrate which controls the relative thickness of the deposit. During the first evaporation a uniform gradient of one metal is deposited. The substrate is then rotated 180° in its own plane and a gradient of another material is superposed. This results in a sample of approximately uniform thickness with pure metal components at the ends and with a composition gradient in between. The procedure is easily extended to permit the production in one evaporation of several samples having different thicknesses. An annealing treatment is usually helpful in promoting diffusion. Representative results on several alloys are described.
L. G. SCHULZ, "Method of Preparing Thin Films of Alloys Suitable for Optical Studies," J. Opt. Soc. Am. 49, 1191-1194 (1959)