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Growing Gd(3)Ga(5)O(15) Single Crystals

IP.com Disclosure Number: IPCOM000078425D
Original Publication Date: 1973-Jan-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 1 page(s) / 13K

Publishing Venue

IBM

Related People

Giess, EA: AUTHOR [+3]

Abstract

Single crystal Gd(3)Ga(5)O(15)(GGG) is a widely used substrate for the liquid phase epitaxial growth of magnetic garnet bubble domain devices. Such crystal GGG is presently grown by the Czochralski technique from melts of generally stoichiometric composition. Because such growth technique for this material requires a high temperature (approximately 1800 degrees C), there has to be utilized therefor iridium metal crucibles. However, because of such high-growth temperature, even iridium crucible corrosion occurs and as a consequence thereof iridium metal inclusions are found in the GGG boules. In addition, these boules have variable lattice constants because GGG is a solid solution.

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Growing Gd(3)Ga(5)O(15) Single Crystals

Single crystal Gd(3)Ga(5)O(15)(GGG) is a widely used substrate for the liquid phase epitaxial growth of magnetic garnet bubble domain devices. Such crystal GGG is presently grown by the Czochralski technique from melts of generally stoichiometric composition. Because such growth technique for this material requires a high temperature (approximately 1800 degrees C), there has to be utilized therefor iridium metal crucibles. However, because of such high- growth temperature, even iridium crucible corrosion occurs and as a consequence thereof iridium metal inclusions are found in the GGG boules. In addition, these boules have variable lattice constants because GGG is a solid solution. The occurrence of these iridium inclusions and the variable-lattice constants of the GGG boules grown by the aforementioned Czochralski technique, consequently adversely influence the performance of bubble domain devices grown on GGG substrates made by this technique.

In the method described, there is set forth a technique for growing single crystal GGG without the occurrence therein of crucible metal inclusions, and wherein there can be exercised advantageous control of stoichiometry.

It has been found that GGG with lattice constant a = 12.377 Angstroms forms in a Ga(2)O(3)-rich melt of GGG. The eutectic occurs at 1580 degrees C at a composition close to 80 mole % of Ga(2)O(3) (in this connection, GGG = 62.5; Ga(2)O(3)). Consequently, single crystal GGG can be produced at temperatures slightly above 1580 degrees C, which enables the employment of the less expensive platinum crucibles rather than the more expensive iridi...