Growth of AlPO.sub.4 crystals
AssigneeBell Telephone Laboratories, Incorporated
InventorsErnest D. Kolb, Robert A. Laudise
Life of this patent
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Abstract
AlPO.sub.4 crystals are isomorphic with quartz and are expected therefore to have several crystal orientations in which the elastic (piezoelectric) constants are relatively insensitive to temperature. The piezoelectric coupling coefficients of AlPO.sub.4 are approximately three times those of quartz. Hydrothermal growth techniques to date have been marginal, and all have employed H.sub.3 PO.sub.4 as the hydrothermal solution. We describe using HCl as the hydrothermal solution and demonstrate the superiority of HCl from the standpoint of solubility and consequent crystal growth rate.
Claims10
Process for growth of AlPO.sub.4 crystals comprising disposing a seed in a hydrothermal medium comprising AlPO.sub.4 solute in a solvent, maintaining the hydrothermal medium at a pressure and temperature sufficient to effect growth of AlPO.sub.4 on the seed, the invention characterized in that the hydrothermal medium comprises an aqueous solution of HCl.
Dependencies are inferred from the claim text.