Unlock instant, AI-driven research and patent intelligence for your innovation.

Large size plank 3+ Preparation method of horizontal directional solidification of ion-doped rare earth orthosilicate series scintillation crystals

A technology of ion doping and orthosilicate, which is applied in the direction of self-solidification, crystal growth, chemical instruments and methods, etc., can solve the problem of poor uniformity of crystal scintillation performance, difficulty in growing by pulling method, uneven concentration distribution, etc. problems, achieve great national defense significance and social benefits, Ce3+ ion concentration distribution is uniform, and the effect of large size

Active Publication Date: 2017-04-12
CHINA ELECTRONICS TECH GRP NO 26 RES INST
View PDF7 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Growth of Ce by pulling method 3+ : Re 2 SiO 5 The limitations of scintillation crystals are: first, due to Ce 3+ The segregation coefficient of ions is low (Ce 3+ : LSO is 0.2, Ce 3+ : YSO is 0.3, Ce 3+ :GSO is 0.6), which will cause Ce in the crystal 3+ The concentration distribution of ions is not uniform, resulting in poor uniformity of crystal scintillation performance
And Ce 3+ : Re 2 SiO 5 The melting point of the crystal is greater than 1900°C, especially Ce 3+ : The melting point of LSO crystal is as high as 2150°C, which is close to the maximum critical temperature (~2300°C) of the iridium crucible, which limits the difficulty of growing large-sized Ce with a diameter of more than 150mm by the pulling method. 3+ : Re 2 SiO 5 scintillation crystal
Third, the cost is high. The pulling method uses precious metal iridium as the crucible material, and the loss of iridium is serious under high temperature and weak oxidizing atmosphere, resulting in an increase in cost

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Large size plank <sup>3+</sup> Preparation method of horizontal directional solidification of ion-doped rare earth orthosilicate series scintillation crystals
  • Large size plank <sup>3+</sup> Preparation method of horizontal directional solidification of ion-doped rare earth orthosilicate series scintillation crystals

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0028] Large-size plate-like Ce of the present invention 3+ : Re 2 SiO 5 A method for preparing a series of scintillation crystals by horizontal directional solidification, the steps are as follows,

[0029] (1) Chemical material in vacuum environment: Ce 3+ : Re 2 SiO 5 Put the bulk pre-crystallized material into a boat-shaped crucible made of molybdenum, where Re is Lu, Y, Gd or a combination of the two, then put the crucible into the single crystal furnace, close the furnace; turn on the vacuum pump, and evacuate the inside of the furnace to 5 ×10 -3 Below Pa, turn on the heating power to heat the raw materials; raise the furnace temperature to 5-10°C above the melting point of the crystal to completely melt the raw materials in the melting zone, then adjust the heating power to keep the melt in a stable convection state, and keep warm for 1 -5 hours;

[0030] (2) Seeding: select Ce of b direction [010] 3+ : Re 2 SiO 5 The crystal acts as a seed crystal and is pla...

Embodiment 1

[0040] Precrystallized high-purity block Ce 3+ : The LSO raw material is loaded into the alcohol-washed boat-shaped molybdenum crucible, wherein the Ce of the raw material placed in the shoulder area of ​​the crucible 3+ The ion concentration is 0.2at.%, the Ce of the raw material placed in the wide area of ​​the crucible 3+ The ion concentration was 0.04 at.%, and the total weight of the pre-crystallized raw material was 4.8 kg. After loading the furnace, vacuumize to 5×10 -3 Pa, then heated up. When the temperature in the high temperature zone rises to ~2160°C, the liquid flow line of the melt is observed, and the heating power is properly adjusted to make the solid-liquid transformation phenomenon of orderly convection just appear on the liquid surface. When the raw material is completely melted, keep it for 3h. Move the pure LSO seed crystal in the [010] direction into the high temperature zone, and the position of the seed crystal is at the tip of the front end of the...

Embodiment 2

[0042] Precrystallized high-purity block Ce 3+ : The YSO raw material is put into the alcohol-washed boat-shaped molybdenum crucible, and the Ce of the raw material placed in the shoulder area of ​​the crucible is 3+ The ion concentration is 0.3at.%, the Ce of the raw material placed in the wide area of ​​the crucible 3+ The ion concentration was 0.09 at.%, and the total weight of the pre-crystallized raw material was 2.9 kg. After loading the furnace, vacuumize to 5×10 -3 Pa, then heated up. When the temperature in the high temperature zone rises to ~2000°C, the melt flow line is observed, and the heating power is properly adjusted to make the solid-liquid transformation phenomenon of orderly convection just appear on the liquid surface. When the raw material is completely melted, keep it for 3h. Move the YSO seed crystal in the [010] direction into the high temperature zone, and the position of the seed crystal is located at the geometric center of the crucible. The mel...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
melting pointaaaaaaaaaa
Login to View More

Abstract

Disclosed is a method for preparing large-sized slablike Ce3+ ion doped rare-earth orthosilicate-series scintillation crystals by means of horizontal directional solidification. The method comprises: forming different temperature regions in a single crystal furnace by heating, wherein the temperature region by which a pre-crystallized material is in a molten state and then forms a melt is a high-temperature region, the temperature region by which a molten raw material is crystallized in a single crystal state is a low-temperature region, and a molten-to-single-crystal transition region naturally forms a temperature gradient region; then, horizontally moving a crucible filled with a raw material, so that the crucible sequentially passes through the high-temperature region, the temperature gradient region and the low-temperature region at a preset speed; and finally, performing annealing and cooling. In the present invention, Ce3+: Re2SiO5 series scintillation crystals are prepared by using a horizontal directional solidification method , and the scintillation crystals have the outstanding advantages of large size, low defects, high quality, more uniform distribution of Ce3+ ion concentration, high utilization rate, less energy consumption, and the like.

Description

technical field [0001] The present invention relates to Ce 3+ Ion-doped rare earth orthosilicate series scintillation crystal growth method, specifically related to a large-scale plate-shaped Ce 3+ : Re 2 SiO 5 The invention relates to a preparation method of (Re=Lu, Y, Gd) series single crystal horizontal directional solidification, which belongs to the technical field of crystal growth. Background technique [0002] Ce 3+ Ion-doped Rare Earth Orthosilicate Crystal Ce 3+ : Re 2 SiO 5 (Re=Lu, Y, Gd, respectively referred to as Ce 3+ :LSO, Ce 3+ : YSO, Ce 3+ :GSO), and mixed crystals formed in different proportions (ie: Ce 3+ : LYSO, Ce 3+ :LGSO, Ce 3+ :GYSO), is a class of high-quality scintillation crystals discovered successively in the 1980s and 1990s. Its basic properties are shown in Table 1. Ce in the table 3+ : Lu / Y of LYSO crystal is not less than 8:2, Ce 3+ : The Lu / Gd ratio of LGSO crystal is not less than 6:4. Because this series of scintillation cr...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C30B11/00C30B29/34
CPCC30B29/34C30B11/00C30B29/22
Inventor 丁雨憧
Owner CHINA ELECTRONICS TECH GRP NO 26 RES INST