CN102002752A - Process method for growing bismuth boronate crystals - Google Patents

Abstract

The invention discloses a process method for growing bismuth boronate crystals. In the traditional method for growing the bismuth boronate crystals, seed crystals are easily twisted off and have defects in the growing process. A resistance Bridgman furnace is adopted in the method for growing the crystals. Because the crystals are grown in the whole crucible, the problem of twisting off of the seed crystals is avoided. In addition, because a low growth rate can be provided by changing the crucible descend rate in the Bridgman method, the crystals are difficult to have growth defects in the growing process.

Description

A kind of growth bismuth boracic acid crystalline processing method

[technical field]

The present invention relates to a kind of growth bismuth boracic acid (BiB3O6 is called for short the BIBO crystal) crystalline processing method, especially a kind of technology of growing high-quality BIBO monocrystalline.

[technical background]

The BIBO crystal is a kind of novel non-linear optic crystal.This crystal shortwave ABSORPTION EDGE is positioned at 270nm.Utilize this crystalline frequency-doubled effect, can obtain high efficiency green glow, blue light and near-ultraviolet light.Two Clock Multiplier Factors that its class is complementary are than KTiOPO4 (KTP), the β-BaB2O4 (BBO) of present widespread use, and LiB3O5 (LBO) or LiIO3 want big.And it see through wide ranges, anti-damage threshold is big, physical and chemical performance is stable, deliquescence is not a kind of very promising non-linear optical crystal material, especially in small-sized blue laser application facet great advantage is arranged.

BIBO belongs to oblique system, the polar growth phenomenon is very serious, because asymmetric growth, the polus animalium imbalance of each crystal face is simultaneously because the BIBO crystal is the borate salt system structure, under high temperature fused state, system viscosity is quite big, make crystal in process of growth, be subjected to very big torsion, cause seed crystal to twist off easily, increase the growth difficulty.Big owing to system viscosity in addition, the flowability of melt is very little in the process of growth, very easily produces various defectives, is mingled with as parcel, growth line and brown etc.Because the BIBO crystal is the consistent compound that melt, all be with the top-seeded solution growth BIBO crystal of growing at present mostly, and the BIBO crystal that grows with top-seeded solution growth is owing to above reason, all can occur growing difficult and produce more defective.

[summary of the invention]

Occur in order to overcome the BIBO crystal that seed crystal twists off and defect problem in process of growth easily, the invention provides falling crucible method and carry out the growth of BIBO crystalline.The technical solution used in the present invention is: adopt resistance-type decline stove to carry out crystal growth.Because crystal is crystallization in whole crucible, it is platinum that crucible records material, so the problem that does not exist seed crystal to twist off.Because falling crucible method can provide the speed of growth more slowly by changing dropping speed of the crucible, make crystal in process of growth, be not easy to occur growth defect in addition.

Place seed crystal in crucible bottom before the crystal growth, situations such as the stray crystal of avoiding causing owing to spontaneous crystallization in the process of growth, polycrystalline.Put a temperature thermocouple at the crucible outer wall that goes out near seed crystal simultaneously, material is a platinum rhodium, comes accurate control growing temperature, avoids seed crystal to melt away in temperature-rise period.Concrete growth parameter(s): decline furnace temperature field is 20-50 ℃/cm, and dropping speed of the crucible is 0.2-2mm/ days, 30-80 ℃/day of crystalline annealing speed.

[description of drawings]

Fig. 1 is growth bismuth boracic acid (BiB3O6 is called for short the BIBO crystal) crystalline method synoptic diagram

[embodiment]

Embodiment one:

(1) by stoichiometric ratio Bi2O3: B2O3=1: accurate weighing Bi2O3 of 3 usefulness electronic balances (high-quality pure) and B2O3 (high-quality pure).

(2) the raw material thorough mixing on ball mill after preparing is even.

(3) mixed raw material is packed in the big platinum crucible, move in the retort furnace, abundant fusion postcooling under 900 ℃ of temperature, and cooled melt ground the platinum crucible of the Φ 15 * 200mm that packs into.

(4) platinum crucible is placed the decline stove, accurately control is warming up to about 708 ℃, and constant temperature 24 hours allows the abundant fusion of melt.

(5) crucible begins the lowering speed decline with 0.8mm/ days, approximately through 25 days, stops to descend, and beginning is annealed to room temperature with 50 ℃/day.

Claims (4)

1. growth bismuth boracic acid crystalline processing method is characterized in that raw material mixed in the crucible of packing into after the fusion of back and cools off, after be positioned in the resistance-type decline stove and carry out crystal growth.

2. a kind of growth bismuth boracic acid crystalline processing method according to claim 1 is characterized in that crucible material can be a platinum.

3. a kind of growth bismuth boracic acid crystalline processing method according to claim 1 is characterized in that placing a temperature measuring equipment in the crucible outside, and temperature measuring equipment can be a platinum rhodium.

4. a kind of growth bismuth boracic acid crystalline processing method according to claim 1 is characterized in that bushing position can regulate, and regulations speed is 0.2-2mm/ days.

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