Method for growing single crystals of thermally unstable ferroelectric materials
US4687538A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 19, 1986 |
| Grant date | Aug 18, 1987 |
| Priority date | — |
| Expiry date | Mar 19, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T117/1092
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method is disclosed for growing thermally unstable ferroelectric materials having the formula MH.sub.2 XO.sub.4, where M is potassium, rubidium, cesium or ammonium; H is hydrogen or deuterium and X is phosphorus or arsenic. The ferroelectric material is heated to melt temperature in a constant volume cylindrical chamber (10) which is moisture-free. Improved crystal formation is accomplished by axially cooling the melt from the bottom end (18) of the chamber by thermal conduction along the chamber longitudinal axis predominantly and only minimally by radial thermal conduction through the sides (16) of the chamber. The axial cooling produces a crystal interface which is flat and perpendicular to the chamber axis and which gradually progresses toward the chamber top to provide uniform growth of a single crystal of ferroelectric material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.