Bismuth silicate-germanate mixed crystal and preparation method thereof

A silicon germanic acid and mixed crystal technology, applied in the field of crystal growth, can solve the problem of low light output and achieve the effects of uniform distribution, low production cost and simple equipment

Inactive Publication Date: 2011-04-13
SHANGHAI INST OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But BSO has the problem of lower light output

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] With high purity 1789g Bi 2 o 3 , 345g of SiO 2 and 2g of GeO 2 as the initial raw material, that is, according to Bi 2 o 3 , SiO 2 and GeO 2 The molar ratio is 2:2.99:0.01 for batching, the initial raw materials are fully mixed, and pre-fired at 650°C for 10h. Then, the mixed initial raw materials are ground to a particle size of 450 nm, and pre-calcined at 800° C. for 10 h to obtain polycrystalline raw materials. BSO crystals with a diameter of 10 mm and an orientation of were used as seed crystals. The pre-fired polycrystalline material and seed crystals were placed in a cylindrical platinum crucible, which was airtight, and placed in a vertical Bridgman crystal growth furnace. Adjust to an appropriate position so that the raw material is in the high temperature zone of the furnace, the furnace temperature is controlled at 1050°C, the temperature gradient of the solid-liquid interface is maintained at 40°C / cm, and the growth rate is controlled at 0.2mm / h. Af...

Embodiment 2

[0030] With high purity 1985g Bi 2 o 3 , 192g of SiO 2 and 334g of GeO 2 as the initial raw material, that is, according to Bi 2 o 3 , SiO 2 and GeO 2 The molar ratio is 2:1.5:1.5 for batching, the initial raw materials are fully mixed, and pre-fired at 700 ° C for 8 hours. Then, the mixed initial raw materials were ground to a particle size of 550 nm, and pre-calcined at 850° C. for 8 hours to obtain polycrystalline raw materials. The BSGO crystal with a diameter of 10 mm and an orientation of was used as a seed crystal, and the pre-fired polycrystalline material and seed crystal were placed in a rectangular cylindrical platinum crucible, which was airtight and placed in a vertical Bridgman crystal growth furnace . Adjust to an appropriate position so that the raw material is in the high temperature zone of the furnace, the furnace temperature is controlled at 1100°C, the temperature gradient of the solid-liquid interface is maintained at 30°C / cm, and the growth rate...

Embodiment 3

[0032] With high purity 3728g Bi 2 o 3, 3g of SiO 2 and 1251g of GeO 2 as the initial raw material, that is, according to Bi 2 o 3 , SiO 2 and GeO 2 The molar ratio is 2:0.01:2.99 for batching, the initial raw materials are fully mixed and uniform, and pre-calcined at 730 ° C for 6 hours to obtain polycrystalline raw materials. Then the mixed initial raw materials were ground to a particle size of 600 nm, and pre-calcined at 850° C. for 8 h. BGO crystals with a diameter of 10 mm and an orientation of were used as seed crystals, and the pre-fired polycrystalline material and seed crystals were placed in 4 cylindrical platinum crucibles, which were airtight and placed in a vertical Bridgman crystal growth furnace . Adjust to an appropriate position so that the raw material is in the high temperature zone of the furnace, the furnace temperature is controlled at 1150°C, the temperature gradient of the solid-liquid interface is maintained at 50°C / cm, and the growth rate is...

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PUM

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Abstract

The invention discloses a bismuth silicate-germanate mixed crystal and a preparation method thereof, belonging to the single crystal field. The molecular formula of the bismuth silicate-germanate mixed crystal is Bi4Si3-xGexO12. The preparation method comprises the following steps: using high-purity Bi2O3, SiO2 and GeO2 as raw materials to fully grind, presinter and obtain a polycrystalline material; and placing seed crystal at the bottom of a crucible in advance, placing the synthesized polycrystalline material in the crucible, and transferring the crucible to a crystal growing furnace while controlling the temperature to 1050-1150 DEG C, the temperature gradient of the solid-liquid interface to 20-50 DEG C/cm and the growth velocity to 0.2-0.5mm/h. The raw material components of the bismuth silicate-germanate mixed crystal provided by the invention are adjustable and are distributed evenly; the mixed crystal has the scintillation property of bismuth silicate and the scintillation property of bismuth germanate, the mixed crystal has large size; the preparation method adopts stable temperature field and simple processing equipment; and multicrystal can grow at the same time, the growth efficiency of the mixed crystal is high, the production cost is low and the mixed crystal is suitable for industrial production.

Description

technical field [0001] The invention relates to a novel scintillation crystal bismuth silicon germanate (Bi 4 Si 3-x Ge x o 12 , BSGO) mixed crystal and a preparation method thereof, belonging to the field of crystal growth. Background technique [0002] Inorganic scintillation crystals are an important class of functional materials, mainly used for the detection of X-rays, γ-rays and other high-energy particles, and are widely used in nuclear medical imaging, nuclear physics detection, space physics detection, safety inspection, geological exploration and industrial production fields . Bismuth germanate (Bi 4 Ge 3 o 12 , BGO) crystals and lead tungstate (PbWO 4 , PWO) crystals are well-known scintillation crystals, which have been successfully used in large electromagnetic calorimeters and medical imaging equipment PET. These two crystals also have their disadvantages: the BGO crystal has a longer decay time, and the crystal composition of GeO 2 It is expensive, w...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C30B29/22C30B11/00C30B11/14
Inventor 徐家跃申慧张彦周鼎金敏江国健房永征
Owner SHANGHAI INST OF TECH
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