Growing method of magnesium fluoride barium single crystal

A technology of barium magnesium fluoride and growth method, which is applied in the direction of single crystal growth, single crystal growth, crystal growth, etc., can solve the problems of difficult to realize single crystal industrial production, fluoride is easy to volatilize, easy to crack and other problems, and reach the crystal size And the shape is easy to control, not easy to crack, and the effect of stable temperature field

Active Publication Date: 2012-07-04
中山昂腾光电科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Growth of BaMgF by pulling method 4 For single crystal, there are the following problems: due to the large temperature gradient near the solid-liquid interface and the anisotropy of the thermal expansion of the crystal itself, cracking is easy to occur; i

Method used

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  • Growing method of magnesium fluoride barium single crystal
  • Growing method of magnesium fluoride barium single crystal

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] The high-purity raw material (99.9%) BaF 2 and MgF 2 Mix evenly according to the molar ratio of 1:1, and then put the mixed powder into figure 1 The device shown is fluoridated at 500-600°C for 5 hours;

[0027] The fluorinated powder and direction, cylindrical CaF 2 The single crystal is placed in a cylindrical platinum crucible with a wall thickness of 0.1mm, and then the crucible is airtight by gas welding;

[0028] Put the platinum crucible into the Bridgman single crystal furnace, and grow barium magnesium fluoride single crystal using the crucible drop method: the furnace temperature is controlled at 1000°C to melt the raw material and the top of the seed crystal, and the temperature gradient at the growth interface is maintained at 30°C / cm. At a rate of 1 mm / hour, transparent cylindrical BaMgF can be grown 4 complete crystals.

Embodiment 2

[0030] The high-purity raw material (99.9%) BaF 2 and MgF 2 Mix evenly according to the molar ratio of 1:1, and then put the mixed powder into figure 1 The device shown is fluorinated at 500-600°C for 6 hours;

[0031] The fluorinated powder and direction, rectangular columnar CaF 2 The single crystal is placed in a rectangular cylindrical platinum crucible with a wall thickness of 0.2mm, and then the crucible is airtight by gas welding;

[0032] Put the platinum crucible into the Bridgman single crystal furnace, and grow barium magnesium fluoride single crystal using the crucible drop method technology: the furnace temperature is controlled at 1450°C to melt the raw material and the top of the seed crystal, and the temperature gradient at the growth interface is maintained at 35°C / cm. At a rate of 2 mm / hour, transparent rectangular columnar BaMgF can be grown 4 complete crystals.

Embodiment 3

[0034] The high-purity raw material (99.9%) BaF 2 and MgF 2 Mix evenly according to the molar ratio of 1:1, and then put the mixed powder into figure 1 The device shown is fluoridated at 500-600°C for 10 hours;

[0035] The fluorinated powder and direction, cylindrical CaF 2 The single crystal is placed in a cylindrical platinum crucible with a wall thickness of 0.3mm, and then the crucible is airtight by gas welding;

[0036] Put the platinum crucible into the Bridgman single crystal furnace, and grow barium magnesium fluoride single crystal using the crucible drop method technology: the furnace temperature is controlled at 1350°C to melt the raw material and the top of the seed crystal, and the temperature gradient at the growth interface is maintained at 40°C / cm. At a rate of 3 mm / hour, transparent cylindrical BaMgF can be grown 4 complete crystals.

[0037] According to the growth method of the present invention, depending on the shape and size of the grown crystals,...

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Abstract

The invention discloses a growing method of a magnesium fluoride barium single crystal, which comprises the following steps of firstly fluorating mixed powder of barium fluoride (BaF2) and magnesium fluoride (MgF2) or BaMgF4 powder; placing powder after fluoration and a seed crystal into a platinum crucible, enabling the crucible to be airtight; and then placing the platinum crucible into a single crystal furnace, and growing the magnesium fluoride barium single crystal by means of a bridgman method. The growing method of the magnesium fluoride barium single crystal has the advantages that a temperature field is stable, no CF4 gas is needed to be introduced in the growing process, the grown BaMgF4 single crystal is good in integrity and free of macro and micro defects, the rate of finished products is high, the size and the shape of the crystal are easily controlled, and the crystal is not easy to craze. In addition, the growing method is simple in processing equipment, convenient in operation, capable of remarkably reducing energy consumption and favorable for achieving industrial production.

Description

technical field [0001] The invention relates to a method for growing a barium magnesium fluoride single crystal, in particular to a method for growing a barium magnesium fluoride single crystal by a crucible descent method, and belongs to the technical field of single crystal growth. Background technique [0002] BaMgF4 is a regular prismatic crystal with lattice constants a=0.58nm, b=1.451nm, c=0.413nm. It belongs to the orthorhombic crystal system with space group Cmc21. Because of its good piezoelectric and ferroelectric properties, it has attracted the attention of Chinese and foreign scholars since the 1960s and 1970s. BaMgF 4 The short-wave transparent wavelength of the crystal can reach 150nm, in which BaMgF 4 The coercive field is about 20kV / cm at room temperature, and the spontaneous polarization is about 8μC / cm 2 , it is estimated that its effective nonlinear coefficient is equivalent to that of quartz crystal, which is 0.3-0.4pm / V. [0003] So far, BaMgF 4 F...

Claims

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Application Information

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IPC IPC(8): C30B29/12C30B11/00
Inventor 武安华徐军苏良碧李红军钱国兴姜林文钱小波王静雅
Owner 中山昂腾光电科技有限公司
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