US3650702A
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Crystal growth of tetragonal germanium dioxide from a flux
Assignee: Motors Liquidation Co
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Filing: 1970-04-15
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Granted: 1972-03-21
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Expires: 1990-04-15
Abstract
Abstract Highly pure single crystals of tetragonal germanium dioxide are grown from a melt containing germanium dioxide in which germanium atoms are octahedrally coordinated to oxygen. In addition to germanium dioxide, the melt includes an oxide of a monovalent metal from Group I of the Periodic Table of the Elements. In preferred embodiments alkali metal oxides are employed, particularly sodium oxide and lithium oxide.
Inventors
- 👤 Don E Swets
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:49
CPC Classifications
C; C30; C30B; C30B15/00; C30B29/00; C30B29/10; C30B29/16
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
36 words
The process as defined in claim 1 wherein the melt empirically consists essentially of germanium dioxide and the oxide of an alkali metal and the germanium oxide content is at least about 89.5 mole per cent.
Claim 2
Dependent Claim
185 words
The process of growing monocrystals of tetragonal germanium dioxide from a melt comprising the steps of: providing a melt composition empirically consisting essentially of germanium dioxide and an oxide of a monovalent metal from Group I of the Periodic Table of the Elements, the proportion of monovalent metal oxide being stoichiometrically less than the eutectic composition between germanium dioxide and the monovalent metal germanate with the lowest identifiable monovalent metal oxide content; heating the composition to a temperAture above the melting point temperature of said eutectic and at which it is completely molten to provide a melt in which germanium atoms are octahedrally coordinated to oxygen and from which tetragonal germanium dioxide crystals can be grown; contacting said melt with a seed crystal of tetragonal germanium dioxide to form a seed-melt contact interface; establishing a freezing isotherm for germanium dioxide at said interface; withdrawing heat from said melt through said seed to induce monocrystalline solidification of tetragonal germanium dioxide onto said seed at said interface; and progressively withdrawing said seed from said melt at a rate commensurate with said monocrystalline solidification of tetragonal germanium dioxide.
Claim 3
Dependent Claim
29 words
The process as defined in claim 3 wherein the monovalent metal is an alkali metal and the alkali metal oxide content is about 5 to 89.5 mole per cent.
Claim 4
Dependent Claim
31 words
The process as defined in claim 4 wherein the alkali metal oxide is at least one selected from the group consisting of cesium oxide, lithium oxide, potassium oxide, and sodium oxide.
Claim 5
Dependent Claim
72 words
The process as defined in claim 5 wherein the monovalent metal oxide is lithium oxide, the lithium oxide content is about 89-93 mole per cent, the lithium oxide is provided in the melt by in situ thermal decomposition of lithium carbonate, and the melt is heated for at least 1 hour in a completely molten condition before commencing crystal growth, to assure octahedral coordination of germanium atoms to oxygen in the melt.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-21 | 1975-09-20 | 1976-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-21 | 1979-09-20 | 1980-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-21 | 1983-09-20 | 1984-03-21 | $7700.00 | Window Closed / Lapsed |