CN100453709C

CN100453709C - Method for developing monocrystal of potassium dihydrogen phosphate in large aperture rapidly

Info

Publication number: CN100453709C
Application number: CNB2004100548949A
Authority: CN
Inventors: 李国辉; 苏根博; 薛丽平; 李征东; 庄欣欣; 贺友平
Original assignee: Fujian Institute of Research on the Structure of Matter of CAS
Current assignee: Fujian Institute of Research on the Structure of Matter of CAS
Priority date: 2004-07-29
Filing date: 2004-07-29
Publication date: 2009-01-21
Anticipated expiration: 2024-07-29
Also published as: CN1727522A

Abstract

The present invention relates to a quick growing method of large-caliber potassium dihydrogen phosphate monocrystal, particularly to a quick growing method of large-caliber potassium dihydrogen phosphate monocrystal. The quick growing method is characterized in that a solution temperature lowering method is adopted; the dosage of a potassium chloride additive in a crystal growing groove is from 1 to 5M%, and the optimal dosage of an EDTA additive is from 0.01 to 0.02 wt%; the initial supersaturation degree reaches 8 DEG C maximally, and the large-caliber potassium dihydrogen phosphate monocrystal grows at room temperature; in general, the temperature is lowered by 0.3 to 0.5 DEG C every day at the initial growing stage; with the quick growth of the monocrystal, the temperature is lowered by 2 DEG C every day.

Description

The quick growth method of a kind of heavy caliber potassium dihydrogen phosphate single crystal

Technical field

The present invention relates to crystal growth, especially relate to heavy caliber potassium primary phosphate (KH ₂PO ₄, be called for short KDP) and the quick growth method of single crystal.

Background technology

The KDP crystal is a kind of good nonlinear optical material, be mainly used in two, three, four frequencys multiplication of laser, especially fine large size KDP crystal has been classified as unique Applied Materials of laser fusion frequency inverted at present in the world, also is the hot subject of current international Study on Crystals Growth.So far great majority still prolong with traditional method and carry out single crystal growing, though usually the falling temperature method of employing, constant temperature flow method, evaporation at constant temperature make-up solution method etc. also to grow quality better, larger-size monocrystalline, but the speed of growth is too slow, growth cycle is oversize, and cost is too high, and efficient is too low.

For the large-sized KDP seed crystal that the obtains heavy caliber crystal that is used to grow, the investigator adopts two kinds of methods both at home and abroad for a long time, a kind of is to adopt repeatedly to cultivate the size that the expanding species method enlarges the KDP bore, but the efficient of this repeatedly expanding species is limited, people such as J.W.Mullin are at J.Appl.Chem, and 20,153 (1970) point out because the KDP crystal respectively only increases along Z-direction basically to process of growth, and the xy bore seldom enlarges, even also dwindles to some extent at later stages.So expanding species method complicated operation repeatedly, efficient is low, and the cycle is long.Another kind method is people's reports on " silicate journal " 1984 the 12 volume third phases such as Su Genbo, cutting the KDP wafer with four Z is spliced in parallel with each other and carries out single crystal growing, through repeatedly eliminating, the method for piecing together the awl growth also only grows the normal awl monocrystalline of 80 * 80 (mm) bore.Experiment shows that the number of wafers that is used to splice is many more, and size is big more, and success ratio is low more, is difficult to reach the degree of practicability.In sum, carry out heavy caliber KDP crystal growth, at first will obtain bigbore seed crystal, just must carry out the method for these two kinds of long period poor efficiency of above-mentioned method of expanding species repeatedly or seed crystal splicing method by traditional growth method.Even obtained the seed wafer of large-size, the final crystal that also will just can grow useful size through the above time of a year and a half can not satisfy far away at present in the world to KDP crystalline demand.

The crystal method for fast growing has obtained very big development in recent years, U.S. LLNL adopt the quick growing technology of some seed crystal realized first large size (the quick growth of 40～50cm) KDP, its Z to and X, Y reaches 10～20mm/d to the speed of growth.But the raw materials used purity of this method is very high, and cost is also long thereupon to raise, and solution is wanted circulating filtration in crystal growing process, the cost of equipment height.

Summary of the invention

Purpose of the present invention just is to propose a kind of new KDP crystal method for fast growing, by add composite additive Repone K and ethylenediamine tetraacetic acid (EDTA) (EDTA) in a small amount in saturated solution, making the trivalent metal ion that influences crystal quick growth under high degree of supersaturation in the solution by complex reaction (mainly is Fe ³⁺, Cr ³⁺, Al ³⁺) the stable complex compound of formation, the minimizing metal ion enters crystal and crystal is grown in the formed liquid phase parcel of crystal cylinder fast under high degree of supersaturation, thereby improve the crystal stability and the crystalline optical quality of growth fast, make under the raw material condition that crystal is grown in the common slow growth groove fast and purity is lower and also can realize, and can engineering amplify, be implemented in and grow large-sized KDP crystal in the big crystal growth groove.

The present invention is with the aqueous solution cooling method heavy caliber KDP crystal of growing fast, but changed in the past only in the way of Z direction growth, adopts additive promoting the KDP crystal along X, Y, and three directions of Z are growth fast simultaneously.This method is to be primary solvent with the redistilled water, add excessive solid top grade KDP raw material, under 35 ~ 80 ℃, be mixed with supersaturated solution, in saturated solution, add the Repone K (its molecular formula is KCl) of 1-5M% and the EDTA additive of 0.01-0.02wt%, use tradition and hang after brilliant method accurately measures the saturation point of saturated solution, through 18～24 hours seed crystals to be put of ultra-fine micropore (aperture is 0.15 μ) membrane filtration back balance.The little wafer that seed crystal adopts the transparent 90 ° of Z of high-quality to cut, with the secondary aquae destillata polish on the silk dry after, be fixed on the crystalline substance that carries that faces upward or downward growth with AB glue and coil.Putting into baking oven is preheated to solution and puts into above-mentioned growth from solution again after synthermal.Initial degree of supersaturation maximum can reach 8 ℃, is about to grow to room temperature when solution cools to than low 8 ℃ of saturation point rapidly, and wherein initial growth stage cooling every day amount is advisable for 0.3～0.5 ℃, and along with crystalline is grown up fast, cooling every day amount can increase to about 2 ℃.Undertaken by above method, its KDP crystalline X, Y, the average day growth speed of three directions of Z can reach 4～11 (mm).

We have measured the KDP saturated solution upgrowth situation of the Repone K that adds different additions, drawing KCl addition best in big crystal growth groove is 1-5M%, the addition of best EDTA is that the average of KDP saturated solution pure under 0.01-0.02wt% and the uniform temp wants wide about 3 ℃, the stability that solution is described has improved, and the quick growth of crystal can be carried out under high degree of supersaturation.

We have also measured the content of metal ion in the crystal, crystalline sees through spectrum and crystalline damage threshold, KDP crystal contrast with slow growth, after finding to add Repone K, crystal each to fast growth an order of magnitude, metal ion content reduces half, and crystalline sees through and be about 15.2J/cm after spectral transmittance and crystalline damage threshold are annealed in 150～160 ℃ of warm areas ²(1.064 μ, 1ns) with at a slow speed quite, reach the use requirement on devices.

The present invention has overcome the KDP crystal usually only in the growth of Z direction, and the very slow problem of long speed.Changed the habitual in the past conventional practice that need obtain bigbore seed crystal by the method for expanding species or polylith seed crystal splicing repeatedly, with little seed crystal method for it; It is slow to the speed of growth simultaneously also to change Z, the state that X, Y are long hardly.Demonstrate several big advantages add Repone K and EDTA in the saturated solution of KDP after: one, crystal are grown in fast in the common crystal growth groove and can carry out, and need not circulation filter; Its two, the effect of the low temperature high saturation that the solubleness of the KDP during than pure state in water can obtain is convenient to the operation of process of growth; Its three, the most important thing is to play KDP Growth Habit regulating effect, promote KDP (x, y, z) three directions growths (promptly realizing comprehensive growth) fast simultaneously.High 5 ~ 10 times growth efficiency of ratio traditional technology method growth KDP crystal that under same appointed condition, can obtain.Thereby shortened growth cycle greatly.And crystal Z is faster than X, Y direction to the speed of growth, and the crystal that grows up to can cut out more quartz crystal device; Its four, the stability of solution improves, and is easy to realize through engineering approaches, can be in large-scale crystal growth groove growing large-size KDP crystal.

The present invention be advantageous in that and adopt little seed crystal to carry out the heavy caliber crystal growth, can settle at one go, grow needed seed size or available crystal apace, easy to operate, the square crystal utilization ratio height that grows simultaneously because seed product size is very little, becomes awl short time of recovery, therefore the extension of the defective of seed crystal itself is few, has saved the solid material in the solution.

Embodiment

Embodiment one: get ultrapure water 22000ml and add about 10000 gram AR level KDP raw materials, add 250 gram AR grade potassium chlorides and 2 gram AR level EDTA then, in with 30000ml ground sealing glass cylinder, be warming up to 70 ℃, constant temperature stirred after 24 hours, after treating that the KDP raw material dissolves fully, accurately to measure the saturation point of solution be 54 ℃ with hanging brilliant method in cooling.With solution at high temperature by the aperture be warming up to behind the membrane filtration of 0.15 μ 70 ℃ than saturation point high 15 ℃ down overheated 24h treat down crystal seed, this helps to improve spontaneous crystallization in stability of solution and the minimizing crystal growing process.Get the square little wafer of 8 * 8 * 3 (mm) size as seed crystal after cutting with transparent complete 90 ° of Z of KDP crystal, on the wetting silk of secondary aquae destillata, polish and dry, being fixed on the fine synthetic glass with AB glue carries on the brilliant dish, (001) faces down, after putting into the baking oven preheating of about 75 ℃ of constant temperature, putting into above-mentioned saturated solution again grows, and cool the temperature to 48.5 ℃ rapidly than low 5.5 ℃ of saturation point temperature, open the Crystal Rotation device, 30 rev/mins rotating speed makes seed crystal (001) face begin into awl, and crystal recovers again.After 24 hours along with crystalline is grown up, the cooling amount that increases progressively with 0.3～1 ℃/day is reduced to 37.8 ℃ gradually, crystal is taken out in quick growth through 20 days when extracting solution equilibria to room temperature at last out, obtain the square transparent heavy caliber KDP crystal that 86 * 94 * 135 (mm) weight reaches 1890 grams.

Embodiment two: get ultrapure water 3000ml and add about 1500 gram AR level KDP raw materials, add 41 gram AR grade potassium chlorides and 0.3 gram AR level EDTA then, in with 5000ml ground sealing glass cylinder, be warming up to 70 ℃, constant temperature stirred after 24 hours, after treating that the KDP raw material dissolves fully, accurately to measure the saturation point of solution be 62 ℃ with hanging brilliant method in cooling.With solution at high temperature by the aperture be warming up to behind the membrane filtration of 0.15 μ 75 ℃ than saturation point high 13 ℃ down overheated 24h treat down crystal seed, this helps to improve spontaneous crystallization in stability of solution and the minimizing crystal growing process.Get the square little wafer of 8 * 8 * 3 (mm) size as seed crystal after cutting with transparent complete 90 ° of Z of KDP crystal, on the wetting silk of secondary aquae destillata, polish and dry, being fixed on the fine synthetic glass with AB glue carries on the brilliant dish, (001) faces up, after putting into the baking oven preheating of about 75 ℃ of constant temperature, putting into above-mentioned saturated solution again grows, and cool the temperature to 55 ℃ rapidly than low 7 ℃ of saturation point temperature, open the Crystal Rotation device, 30 rev/mins rotating speed makes seed crystal (001) face begin into awl, and crystal recovers again.After 24 hours along with crystalline is grown up, the cooling amount that increases progressively with 0.3～2 ℃/day is reduced to 51.2 ℃ gradually, through 3 days quick growth, take out crystal when extracting solution equilibria at last out to room temperature, obtain the square transparent heavy caliber KDP crystal that 31 * 32 * 33 (mm) weight reaches 53.2 grams.

Claims

1. the quick growth method of heavy caliber potassium dihydrogen phosphate single crystal is aqueous solution cooling method, it is characterized in that:

(1) consumption of additive Repone K is 1-5M% in the crystal growth groove, and the consumption of additive EDTA is 0.01-0.02wt%;

(2) initial degree of supersaturation maximum reaches 8 ℃, grows to room temperature; Wherein initial growth stage cooling every day amount is 0.3～0.5 ℃, and along with crystalline is grown up fast, cooling every day amount increases to 2 ℃.