| 摘要 |
1,089,973. Piezoelectric elements. CLEVITE CORPORATION. March 19, 1965 [April 29, 1964], No. 11860/65, Heading H1E. A piezoelectric element is formed by sublimation of material composed of Class II-VI compounds whereby a polycrystalline mass of dihexagonal polar crystals having polar orientation is formed. The materials may be selected from the group consisting of CdS, CdSe, ZnO, BeO, ZnS (wurtzite) and solid solutions thereof. Sublimation may be carried out in a tubular quartz vessel 24 partly enclosed in a furnace 22, the vessel 24 being arranged so that sublimation of material 28 at the centre of the furnace takes place at a temperature of about 750‹ C. and deposition of a crystalline mass takes place near the wall of the furnace at a temperature of about 400‹ C. The vessel is evacuated to below 1 mm. of mercury. The deposit is in the form of acicular crystals having their c axes oriented at right-angles to the walls of the vessel. A thin electromechanical transducer may be formed by deposition on to a conductive or non-conductive substrate arranged at right angles to the axis of the vessel. When the substrate is non-conductive (e.g. glass) an electrode may be deposited first. |
