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Growing method of carbon-doped sapphire crystal by EFG method

A technology of sapphire crystal and guided mode method, applied in the direction of single crystal growth, single crystal growth, crystal growth, etc., can solve the problems of complicated process, difficult to ensure uniform distribution of carbon, difficult to obtain uniform quality, etc. Thermoluminescence and photoluminescence properties, the effect of good crystal quality

Inactive Publication Date: 2008-10-08
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

The premise of this method is to grow a high-quality rod-shaped sapphire crystal, and then reduce and anneal. The process is relatively complicated, and it is difficult to ensure the uniform distribution of carbon in the sapphire crystal, that is, it is difficult to obtain α-Al with uniform quality 2 o 3 :C crystal

Method used

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  • Growing method of carbon-doped sapphire crystal by EFG method
  • Growing method of carbon-doped sapphire crystal by EFG method
  • Growing method of carbon-doped sapphire crystal by EFG method

Examples

Experimental program
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Effect test

Embodiment 1

[0023] Example 1: Flake α-Al 2 o 3 : Preparation of C crystals

[0024] Weigh 500 grams of 99.999% α-Al 2 o 3 , cold-pressed into a cylindrical block at 200MPa, and then sintered at 1500°C for 24 hours in a silicon-molybdenum rod high-temperature furnace. figure 1 It is the present invention to grow flake α-Al 2 o 3 : Schematic diagram of molybdenum crucible and mold used for C crystal. Open the top cover 1 and the sintered α-Al 2 o 3 The block is put into the crucible 2 and put into the pulling furnace. Vacuum the pulling furnace to 5×10 -3 Pa, graphite resistance heating continues to heat up to 2080 ° C, constant temperature for 0.5 hours; control the temperature at the top of the guide mode 3 to make it slightly higher than the melting point of the crystal, and then Direction seed crystal is put down, and it is contacted with the molten liquid surface of guide mold 3 tops, pay attention to the melting of observation seed crystal end. The end of the seed crystal ...

Embodiment 2

[0026] Example 2: Growth of α-Al in different shapes 2 o 3 :C crystal

[0027] in α-Al 2 o 3 :C In the application process of crystals, there may be specific requirements for crystal shapes, such as rods, tubes, fibers, etc. The most prominent feature of the guided mode method is that it can grow crystals with special shapes, and the shape of the crystals is controlled by designing the cross-section of the top of different guided mode molds. Growth of tubular and rod-shaped α-Al 2 o 3 : The schematic diagram of the crucible with the guide mode mold designed by C crystal is as Figure 4 with Figure 5 As shown, the crystal growth process is the same as in Example 1. Anneal the grown crystals under high temperature hydrogen conditions to obtain α-Al with excellent thermoluminescent and optical luminescent properties 2 o 3 :C crystal.

Embodiment 3

[0028] Example 3: α-Al obtained at different hydrogen annealing temperatures 2 o 3 :C crystal

[0029] α-Al grown by guided mode method 2 o 3 :C crystals were kept at 1000°C, 1250°C, and 1500°C for 80 hours under hydrogen atmosphere respectively. It was found that the crystals after hydrogen annealing at different temperatures have thermoluminescence and photoluminescence characteristics, but the intensity of thermoluminescence and photoluminescence changes under the same irradiation dose, which is mainly related to the F color center existing in the crystal . With the increase of hydrogen annealing temperature, the oxygen vacancies in the crystal gradually increase, resulting in the increase of F color center defects in the crystal, so α-Al 2 o 3 : The luminescence peak of C crystal at 190°C is enhanced, and the luminescence peak intensities at 190°C of crystals annealed at 1000°C, 1250°C, and 1500°C measured by X-ray irradiation for 10 seconds are 2300cps, 6700cps, and...

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Abstract

Disclosed is a growth method of carbon-doped sapphire crystal through a guided mode method, which is characterized in that the guide mode method and a molybdenum-die are adopted for the growth of Alpha-Al2O3:C crystals. The alumina block with a certain weight through the high temperature sintering is disposed in a crucible of the molybdenum guided mode die, loaded inside a pulling furnace that is in vacuum-pumping to 10<-3> to 10<-4>Pa. Through the resistance heating, the temperature is continuously increased to 2050 to 2100 DEG C and then in constant temperature for 0.5 to 1 hour. Afterwards, the seed crystals are used for the growth of Alpha-Al2O3:C crystals. The Alpha-Al2O3:C crystals obtained from the growth are disposed in an annealing furnace of 1000 to 1500 DEG C under an atmosphere of hydrogen to preserve the heat for 50 to 100 hours. With the invention, the Alpha-Al2O3:C crystals with excellent thermoluminescence and optically stimulated luminescence properties can rapidly grow. Therefore, the invention can be applied in the manufacturing of highly sensitive thermoluminescence and optically stimulated luminescence detector.

Description

technical field [0001] The present invention relates to carbon-doped sapphire crystal (hereinafter referred to as α-Al2O3:C), especially a method for growing carbon-doped sapphire crystal by guided mode method, α-Al 2 o 3 :C crystals are mainly used in the manufacture of thermoluminescence and photoluminescence detectors. Background technique [0002] In 1990, Professor M.S.Akselrod first reported α-Al 2 o 3 :C crystal and found that it has very excellent thermoluminescent (Thermoluminescent, TL for short) properties (M.S.Akselrod et.al.Highly sensitive thermoluminescent anion-defective α-Al 2 o 3 : C single crystal detectors, Radiation Protection Dosimetry, 1990, 32: 15-20). α-Al 2 o 3 The luminescence peak temperature of :C crystal is around 187°C, the peak wavelength of thermal luminescence after irradiation is 420nm, the thermoluminescence sensitivity is 40-60 times that of LiF:Mg, Ti, and the background threshold dose is only 10 -6 Gy, its dose response is linea...

Claims

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Application Information

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IPC IPC(8): C30B29/20C30B15/04C30B15/24
Inventor 杨新波徐军李红军程艳赵广军周国清
Owner SHANGHAI INST OF OPTICS & FINE MECHANICS CHINESE ACAD OF SCI
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