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Method for lifting crystal growth by induction heating in reducing atmosphere

A technology for induction heating and growing crystals, which is applied in the directions of self-melt pulling method, single crystal growth, crystal growth, etc. It can solve the problems of high cost, high equipment requirements, and high maintenance costs, and achieve cost reduction, low price, and general use strong effect

Inactive Publication Date: 2009-11-11
SHANGHAI INST OF OPTICS & FINE MECHANICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to use platinum, iridium precious metal crucible and easy cracking zirconia heat preservation cover to exist high cost problem when above-mentioned existing pulling method grows crystal, and above-mentioned existing improved pulling method using tungsten, molybdenum crucible For problems such as high equipment requirements and high maintenance costs, a method for inductively heating and pulling growing crystals in a reducing atmosphere is provided

Method used

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  • Method for lifting crystal growth by induction heating in reducing atmosphere
  • Method for lifting crystal growth by induction heating in reducing atmosphere

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] Embodiment 1: use molybdenum crucible, graphite felt grows sapphire (Al 2 o 3 ) crystal

[0043] First, put the molybdenum crucible 8 on the hard graphite felt 9, then wrap the multi-layer soft graphite felt 6 outside the hard graphite felt 9 and the crucible 8, then put it in the quartz barrel 5, and put it into the pulling crystal furnace as a whole In the induction coil 7 of the furnace, place it on the tray 17 at the bottom of the furnace, place the Al 2 o 3 Put the raw materials into the crucible 8, place a hard graphite felt insulation cover 2 above the molybdenum crucible 8, cover the hard graphite felt insulation cover 1, close the furnace door, and vacuumize. After the vacuum degree reaches better than 20 Pa, fill the Argon protective atmosphere, using the common process of growing sapphire by pulling method for crystal growth. Anneal the grown sapphire crystal in a muffle furnace at 1600°C for 2 hours in an air atmosphere to eliminate the oxygen ion vacanc...

Embodiment 2

[0044] Embodiment 2: use molybdenum crucible, graphite felt grows titanium sapphire (Al 2 o 3 : Ti 3+ ) crystal

[0045] First, put the molybdenum crucible 8 on the hard graphite felt 9, then wrap the multi-layer soft graphite felt 6 outside the hard graphite felt 9 and the crucible 8, then put it in the quartz barrel 5, and put it into the pulling crystal furnace as a whole In the induction coil 7 of the furnace, place it on the tray 17 at the bottom of the furnace, place the Al 2 o 3 Put the Ti raw material into the molybdenum crucible 8, place a hard graphite felt insulation cover 2 on the top of the molybdenum crucible 8, cover the hard graphite felt insulation cover 1, close the furnace door, vacuumize, and treat that the vacuum degree is better than 20 Pa. , filled with argon protective atmosphere, and the crystal growth is carried out by the common process of growing titanium sapphire by the pulling method. After the growth, the titanium sapphire crystal is first a...

Embodiment 3

[0046] Embodiment 3: use tungsten crucible, graphite felt, zirconia insulation cover growth neodymium-doped yttrium aluminum garnet (Nd:Y 3 al 5 o 12 ) crystal

[0047]First, put the tungsten crucible 8 on the hard graphite felt 9, then wrap the multi-layer soft graphite felt 6 outside the hard graphite felt 9 and the tungsten crucible 8, then put it in the quartz barrel 5, and put it into the pulling crystal furnace as a whole In the induction coil 7 inside, place on the tray 17 at the bottom of the furnace, put Nd:Y 3 Al 5 o 12 Put the raw materials into the tungsten crucible 8, then place the zirconia brick insulation cover 2 on the top of the tungsten crucible 8, cover the zirconia insulation cover 1, close the furnace door, vacuumize, fill in the nitrogen protective atmosphere, and grow by pulling method Yttrium aluminum garnet crystal growth is performed by a common process. The yttrium aluminum garnet crystal after the growth is first annealed in the muffle furnac...

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Abstract

A method for lifting crystal growth by induction heating in reducing atmosphere is characterized by placing a tungsten crucible or a molybdenum crucible on a hard graphite felt; wrapping a plurality of layers of soft graphite felt around the hard graphite felt and the crucible; sleeving the wrapped hard graphite felt and the crucible in a quartz cylinder; wholly putting the quartz cylinder in an induction coil inside a crystal-lifting furnace, especially on a tray at the bottom of hearth; charging materials to the crucible; arranging and covering a hard graphite felt insulation cover or a zirconia insulation cover above the crucible; closing the door of the furnace and carrying out vacuumization; injecting shielding gas till positive pressure is reached; carrying out crystal growth by using a conventional method; and carrying out anneal in the atmosphere of air, oxygen or other atmosphere after the crystal growth is finished. The method has the advantages of utilizing the graphite felt to provide the reducing atmosphere so as to be capable of adopting the low-cost tungsten crucible or molybdenum crucible and realize the growth of sapphire and lithium aluminate and other crystals with low cost, thus having better universality, requiring simple equipments and especially being suitable for production of large scale.

Description

technical field [0001] The invention relates to a method for growing crystals by induction heating and pulling, in particular to a method for growing crystals by induction heating and pulling in reducing atmosphere. Background technique [0002] The pulling method, also known as the Czochralski method, is a method invented by J. Czochralski in 1917 to grow high-quality single crystals from a melt. This method enables the growth of important gemstone crystals such as sapphire, ruby, yttrium aluminum garnet, gadolinium gallium garnet and spinel. [0003] However, the growth of compound crystals by the pulling method usually requires expensive platinum, iridium and other precious metal crucibles, especially in the process of growing high-temperature crystals, the crucible generally has a loss of 2-3‰. In addition, the traditional pulling method usually uses zirconia sand and zirconia bricks as insulation materials. Among them, the zirconia brick insulation cover is easy to cra...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C30B15/00C30B15/14
Inventor 周圣明林辉
Owner SHANGHAI INST OF OPTICS & FINE MECHANICS CHINESE ACAD OF SCI
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