This paper describes the theory and construction of apparatus for the vapor deposition of highly resistive, highly oriented, piezoelectrically active cadmium sulfide films from the constituent elements. The cadmium and sulfur are evaporated from a double coaxial isothermal source, the composition of the vapor beam being determined predominantly by the area of an orifice in each source. The source operates at 420deg;C, and condensation rates of 300 Aring;sol;sec are readily obtained. The deposition rate may be varied over a wide range (say, 15 to 1) with little resultant change in resistivity. Films were deposited on fused quartz to serve as electromechanical transducers. A shear mode coupling constantktof 0.12 was measured. The longitudinal mode signal level was 46 dB below that of the shear mode at the upper 3 dB shear mode frequency. A longitudinal modektof 0.12 has been obtained with a shear mode suppression of 60 dB.
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