Combined different valence ions doped crystal of lead tungstate with high light yield, and prepartion method

An ion doping, lead tungstate technology, applied in crystal growth, chemical instruments and methods, single crystal growth, etc., can solve the problems of low light yield, slow luminescence, insignificant increase in light yield, etc. The effect of high volume, high yield, and low proportion of slow-emitting components

Inactive Publication Date: 2007-12-26
SHANGHAI INST OF CERAMIC CHEM & TECH CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

It is mainly aimed at the problems that the light yield of lead tungstate crystals is low at present and the increase of light yield is not significant after the introduction of a certain dopant alone or the slow component of luminescence is obviously introduced

Method used

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  • Combined different valence ions doped crystal of lead tungstate with high light yield, and prepartion method

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] 1. High purity PbO and WO with a purity of 99.99% 3 The powder is precisely prepared according to the stoichiometric ratio, and is melted in a platinum crucible to make a high-density PWO polycrystalline ingot.

[0022] 2. A crucible of 15×15×200mm is made of single-layer platinum with a thickness of 0.10mm;

[0023] 3. The PWO single crystal with an orientation of and a size of 14×14×50mm is used as the seed crystal;

[0024] 4. With PbF2 and Sb 2 o 3 As two avalent dopants, 1000ppm (at%) PbF was added after loading the raw materials into a platinum crucible 2 and 1000ppm(at%) of Sb 2 o 3 Dopant, then install the seed crystal, and close the platinum crucible;

[0025] 5. Put the platinum crucible with raw material and seed crystal into the downcomer;

[0026] 6. Raise the furnace temperature to 1200°C at a rate of 80°C per hour, then keep it warm for about 4 hours, and then gradually rise the downpipe, and gradually melt the raw materials in the platinum crucib...

Embodiment 2

[0030] 1. High-purity PbO and WO with a purity of 99.99% 3 Powder, precisely prepared according to stoichiometric ratio, mixed with 10000ppm (at%) MoO 3 The dopant is melted in a platinum crucible to make a highly dense PWO polycrystalline ingot.

[0031] 2. A crucible of 25×25×450mm is made of single-layer platinum with a thickness of 0.10mm;

[0032] 3. The PWO single crystal with an orientation of and a size of 24×24×60mm is used as the seed crystal;

[0033] 4, process step is the same as embodiment 1.4

[0034] 5. Put the platinum crucible with raw material and seed crystal into the downcomer;

[0035] 6. Raise the furnace temperature to 1250°C at a rate of 80°C per hour, then keep it warm for about 6 hours, and then gradually rise the lower tube, and the raw materials in the platinum crucible will gradually melt until they are all melted and then keep warm for about 2 hours. The crystal growth starts at 25 ℃, the temperature gradient in the growth area is 25°C / cm, a...

Embodiment 3

[0039] 1. High-purity PbO and WO with a purity of 99.99% 3 Powder, precisely prepared according to the stoichiometric ratio, mixed with 1000ppm (at%) of V 2 o 5 The dopant is melted in a platinum crucible to make a highly dense PWO polycrystalline ingot.

[0040] 2, process step is the same as embodiment 2.4~2.7;

[0041] 3. In this embodiment, one furnace can grow 4 PWO crystals;

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Abstract

This invention relates to a method for preparing heterovalent ions-doped high-luminescence-yield lead tungstate crystal and its preparation method. The high-luminescence-yield lead tungstate crystal is doped with F- 100-8000 ppm, Sb3+ 100-5000 ppm, and Mo6+, V5+, Nb5+, Zr4+, and Ti4+ 0-10000 ppm, and is prepared via modified Bridgman method by using platinum crucible. The method can be used for preparing several strands of lead tungstate crystals in one process, and is suitable for mass production. The obtained heterovalent ions-doped high-luminescence-yield lead tungstate crystal has such advantages as rapid attenuation and high luminescence yield.

Description

technical field [0001] The invention relates to a heterovalent ion synergistically doped high-light-yield lead tungstate crystal and a preparation method thereof, belonging to the field of crystal growth. Background technique [0002] Since the 1990s, the rapid development of nuclear medicine imaging technology (such as X-CT: X-ray computed tomography, SPET-single photon emission computed tomography, PET-positron electron tomography) has greatly promoted the scintillation crystal and inspire people to explore medical scintillation crystals with excellent performance. The main requirements of medical scintillation crystals are: high density, high luminous efficiency, short decay length and decay time. Among them, bismuth germanate (BGO) crystal is the most widely used in PET at present, but its decay time is too long (greater than 300ns), which is not conducive to the improvement of image resolution; while lutetium silicate (LSO) crystal has a short Decay time (40ns) and hi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C30B29/32
Inventor 严东生谢建军袁晖廖晶莹沈炳孚童乃柱邵培发叶崇志熊巍李培俊吴泓澍展宗贵陈良朱翔宇
Owner SHANGHAI INST OF CERAMIC CHEM & TECH CHINESE ACAD OF SCI
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