JP3492398B2 - Method for growing Pb-containing β-BBO single crystal - Google Patents

Method for growing Pb-containing β-BBO single crystal

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Publication number
JP3492398B2
JP3492398B2 JP23804093A JP23804093A JP3492398B2 JP 3492398 B2 JP3492398 B2 JP 3492398B2 JP 23804093 A JP23804093 A JP 23804093A JP 23804093 A JP23804093 A JP 23804093A JP 3492398 B2 JP3492398 B2 JP 3492398B2
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Japan
Prior art keywords
growing
single crystal
bbo
bpbo
phase
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Expired - Lifetime
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JP23804093A
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Japanese (ja)
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JPH0789796A (en
Inventor
剛 犬井
英郎 矢橋
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Ibiden Co Ltd
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Ibiden Co Ltd
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Description

【発明の詳細な説明】 【0001】 【産業上の利用分野】本発明は、非線形光学結晶:ベー
タ・バリウムボレイト(β−BaB2O4、以下は単に「β−
BBO」と略記する。)に鉛を混入させた結晶(β−
(Ba、Pb)B2O4、以下は単に「β−BPBO」と略記す
る。)を育成する方法に関する。 【0002】 【従来の技術】ベータ・バリウムボレイト単結晶(β−
BBO)は、化学沈澱により得られたバリウムボレイト
水和物(BaB2O4・4H2O )を焼成したものを育成原料と
して用いることにより、フラックスを用いない直接引き
上げ法で育成することができる(特開平2−172892号公
報参照) 。一方、このBBOの非線形光学的性質を向上
させることを目的として該BBO結晶中におけるBaの一
部をPbで置き換えた結晶(β−BPBO)を育成するこ
とも試みられている。 【外1】しかし、これらの既知技術では、育成される結晶が非線
形光学的に不活性なα相(高温相)の結晶であり、非線
形光学的活性のβ相(低温相)の結晶を育成することは
困難であった。 【0003】 【発明が解決しようとする課題】すなわち、前記BPB
Oは一般に、塩化バリウム(BaCl12・2H2O) とほう酸(H
3BO3) の共沈物からBBOを作製し、さらにこれにPbO
を添加してβ−BPBO育成原料としていた。ところ
が、このような方法では、溶体中でPbO の分布が不均一
になるために、β相からα相への転移が起こり、非線形
光学的に活性なβ−BPBOの作製を困難にしていたの
である。 【0004】本発明の目的は、従来技術が抱えている上
述した問題点を克服すること、即ち、非線形光学的に活
性なβ−BPBOを安定して確実に作製する技術を確立
することにある。 【0005】 【課題を解決するための手段】本発明が掲げる上述した
目的に対し、主として、Pbの不均一分布を解消すること
によって、β−BPBO単結晶の育成中、β相を安定維
持させるための方法について検討した。その結果、発明
者らは、鉛を混入させたベータ・バリウムボレイト(β
−(Ba、Pb)B2O4)単結晶を融液から直接引き上げ法で
育成するに当たっては、ほう酸 (H3BO3), 塩化バリウム
(BaCl2・2 H2O)および塩化鉛( PbCl2)の混合水溶液から
Pb含有バリウムボレイト水和物((Ba、Pb) B2O4・4H2
O )を沈澱させ、この沈澱物を焼成して単結晶育成原料
((Ba、Pb) B2O4)として結晶の育成を図ることを特徴
とするPb含有β−BBO単結晶の育成方法、を開発する
に到った。 【0006】 【作用】本発明の特徴の1つは、従来の酸化鉛(PbO) に
代えて塩化鉛(PbCl2) を使うことにある。このPbCl2
着目した理由は、PbO は水に不溶性で共沈溶液を得るこ
とができないが、PbCl2 は水に可溶性で共沈溶液を得る
ことができるからである。そして、このPbを塩化バリウ
ムやほう酸と共に共沈させることができれば、このPbが
原子レベルで混合されるために、従来のようなPbの不均
一分布がなくなり、β相からα相への転移を効果的に抑
制できるようになる。 【0007】一般に、BBOなどをフラックスを用いず
に直接引き上げ法にて育成するためには、原料に化学沈
澱法により製造したBBOの4水和物を用いる必要があ
るとされていた。それは、化学沈澱法によって製造され
た原料の場合、非常に化学量論的(stoichiometric) な
特性に優れ、また、結晶性の良いものも得られるからで
ある。従って、このような原料を焼成すると、β相構造
を持つBBOの原料を安定して確実に得ることができる
のである。 【0008】特に、本発明においては、β相構造を持つ
BPBOを安定して育成させるために、上記PbCl2 をB
BO原料に対し後から加えるのではなく、このPbを化学
沈澱の際に共沈させることによって予混合させ、このこ
とにより得られるBPBO水和物(β−(Ba、Pb) B2O4
・4H2O )を単結晶育成用原料として用いることにし
た。 【0009】次に、かかるBPBO水和物の共沈溶液作
製に当たっては、該水溶液中のBaイオンとPbイオンの比
を、95/5〜99/1の範囲, より好ましくは96/4〜98
/2の範囲内とすることが望ましい。なお、このイオン
比の上限値は、β−BBO以外の結晶(第2相)の出現
を阻止するレベルであり、一方、下限値は、Pb添加によ
る非線形光学効果の向上を得るための最低ラインであ
る。 【0010】さらに、本発明においては、上記共沈溶液
の pH調整も必要であり、 pH:11〜13のときに共沈す
る。望ましくは、水酸化ナトリウムを用いてこの pHを
12.6に調整して共沈させるとよい。 【0011】次に、β−BPBO単結晶育成用原料を得
るために、前記混合水溶液からBPBO水和物を共沈さ
せ、次いでこの水和物を純水にて十分に洗浄し、その
後、この共沈水和物を、800 〜850 ℃の温度にて大気中
で焼成する。このような処理により、結晶性の良いβ相
を持ったBPBOの原料を得ることができる。そして、
この原料を用いることにより、既知の直接引き上げ法、
例えば、チョコラルスキー法, ブリッジマン法などによ
ってβ相構造を持ったBPBO単結晶を育成する。 【0012】 【実施例】以下、本発明の好適実施例について説明す
る。 (1) 塩化バリウム(BaCl2・2H2O) 0.98molと、ほう酸
(H3BO3)1mol と、塩化鉛(PbCl2) 0.02molとを、2
リットルの水に溶解し、その混合水溶液の Ba/Pb 比を 98/
2 に調整すると共に、pHを12.6に調製して(Ba、Pb)
B2O4・4H2Oの水和物を共沈させた。 (2) 次に、上記共沈生成物(Ba、Pb) B2O4・4H2Oを洗
浄した後、850 ℃にて3時間焼成し、β相構造を持つ
(Ba、Pb)B2O4を得た。その後、この焼成原料を白金る
つぼに充填し、高周波引き上げ炉中で育成した。この育
成条件は、シード回転数:20rpm 、引き上げ速度:3 mm
/hr、雰囲気は大気中の条件で育成した。なお、育成方
向は、C軸方向とした。その結果、直径10mm、長さ20mm
の単結晶を育成した。 (3) そこで、上記単結晶に、Nd:YAGレーザ光の1.06
μmの光を照射したところ、第2高調波である0.53μm
の緑色光が確認され、非線形光学活性であるβ相構造を
持ったβ−BPBOが育成されていることが確かめられ
た。 【0013】 【比較例1】 (1) 塩化バリウム(BaCl2・2H2O)1mol と、ほう酸(H3
BO3)1mol を、2リットルの水に溶解し、pHを12.6に
調製して Ba B2O4・4H2Oを沈澱させた。これを850 ℃に
て3時間焼成してβ相構造を持つBBOを作製した。 (2) 上記BBOを1mol 秤量し、これにPbO を0.2 mol
添加し、乳鉢でよく混合した。この原料を白金るつぼに
充填し、高周波引き上げ炉中で育成した。この育成条件
は、シード回転数:20rpm 、引き上げ速度:3mm/hr、
雰囲気は空中で行った。また、育成方向はC軸引き上げ
とした。 (3) しかし、引き上げ条件は上記実施例と同様であるに
もかかわらず、引き上げられてくる結晶は非線形光学不
活性なα相しか得られなかった。 【0014】 【比較例2】基本的に実施例と同じ条件の下で、 BaCl2
・2H2O 0.93 mol , ホウ酸(H3BO3)1mol 、塩化鉛(Pb
Cl2) 0.07molとし、混合水溶液のBa/Pb比は93/7 とし
た。その結果、結晶が黄色に着色し、光学結晶として使
用できなかった。 【0015】 【比較例3】基本的に実施例と同じ条件として、とく
に、 BaCl2・2H2O 0.995mol , ホウ酸(H3BO3)1mol 、
塩化鉛(PbCl2) 0.005mol で、混合水溶液のBa/Pb比は
99.5/0.5 とした。その結果、得られたPb含有β−BB
Oについては、非線型特性の向上が見られなかった。 【0016】 【発明の効果】以上説明したとおり、本発明によれば、
フラックスを用いない直接引き上げ法でBBOにPbを混
入させたβ−BPBO単結晶を育成する際、非線形光学
的に活性であるβ相構造を持ったBPBO単結晶を容易
に育成することができる。
DETAILED DESCRIPTION OF THE INVENTION [0001] The present invention relates to a nonlinear optical crystal:
Ta barium borate (β-BaBTwoOFour, The following is simply “β-
BBO ". ) Mixed with lead (β-
(Ba, Pb) BTwoOFour, The following is simply abbreviated as “β-BPBO”
You. ) On how to nurture. [0002] 2. Description of the Related Art Beta-barium borate single crystals (β-
BBO) is a barium borate obtained by chemical precipitation.
Hydrate (BaBTwoOFour・ 4HTwoO) is fired and used as the raw material
Direct use without flux
It can be raised by the raising method (Japanese Patent Laid-Open No. 2-172892)
Report). On the other hand, the nonlinear optical properties of this BBO have been improved.
Of Ba in the BBO crystal for the purpose of
To grow a crystal (β-BPBO) with the part replaced by Pb
Has also been tried. [Outside 1]However, in these known techniques, the grown crystal is non-linear.
Formally optically inert α-phase (high-temperature phase) crystal, non-linear
To grow a β-phase (low-temperature phase) crystal with optically active
It was difficult. [0003] That is, the BPB
O is generally barium chloride (BaCl12・ 2HTwoO) and boric acid (H
ThreeBOThreeBBO was prepared from the coprecipitate of
Was added to obtain β-BPBO growing material. Place
However, with such a method, the distribution of PbO in the solution is not uniform.
Phase transition from β phase to α phase occurs,
Making it difficult to make optically active β-BPBO
It is. [0004] The object of the present invention is to overcome the disadvantages of the prior art.
Overcoming the above-mentioned problems, that is,
Established technology to stably and reliably produce stable β-BPBO
Is to do. [0005] SUMMARY OF THE INVENTION According to the present invention, there is provided the above-mentioned configuration.
For the purpose, mainly to eliminate the uneven distribution of Pb
During the growth of β-BPBO single crystal,
We considered about the method to make it hold. As a result, the invention
Are beta-barium borate mixed with lead (β
− (Ba, Pb) BTwoOFour) Single crystal is pulled directly from the melt
When growing, boric acid (HThreeBOThree), Barium chloride
(BaClTwo・ 2 HTwoO) and lead chloride (PbClTwo)
Pb-containing barium borate hydrate ((Ba, Pb) BTwoOFour・ 4HTwo
O) is precipitated, and the precipitate is calcined to produce a single crystal growing material.
((Ba, Pb) BTwoOFourThe feature is to grow crystals as
Method for growing a Pb-containing β-BBO single crystal
Reached. [0006] One of the features of the present invention is that conventional lead oxide (PbO)
Instead of lead chloride (PbClTwo). This PbClTwoTo
The reason we focused on was that PbO was insoluble in water and could give a coprecipitated solution.
But PbClTwoIs soluble in water and gives a coprecipitation solution
Because you can do it. And this Pb
If this Pb can be co-precipitated with
Due to mixing at the atomic level, the conventional Pb unevenness
One distribution disappears, effectively suppressing the transition from β phase to α phase
Control. In general, BBO or the like is used without using flux.
In order to grow by direct pulling method,
It is necessary to use tetrahydrate of BBO produced by the precipitation method.
It was supposed to be. It is manufactured by chemical precipitation method
Raw material is very stoichiometric
It has excellent properties and also has good crystallinity.
is there. Therefore, when such a raw material is fired, the β phase structure
Of BBO with stable and reliable
It is. In particular, the present invention has a β-phase structure
In order to stably grow BPBO, the above PbClTwoTo B
Instead of adding it to the BO raw material later, this Pb is
This is premixed by co-precipitation during precipitation and this
And BPBO hydrate (β- (Ba, Pb) BTwoOFour
・ 4HTwoO) as raw material for growing single crystals.
Was. Next, a coprecipitation solution of BPBO hydrate is prepared.
In the production, the ratio of Ba ion to Pb ion in the aqueous solution was
In the range of 95/5 to 99/1, more preferably 96/4 to 98
/ 2 is desirable. In addition, this ion
The upper limit of the ratio is determined by the appearance of crystals other than β-BBO (second phase).
Level, while the lower limit is due to the addition of Pb.
Is the minimum line for obtaining improved nonlinear optical effects.
You. Further, in the present invention, the above coprecipitation solution
PH adjustment is necessary, and co-precipitates when the pH is 11 to 13.
You. Preferably, the pH is adjusted using sodium hydroxide.
Adjust to 12.6 and co-precipitate. Next, a raw material for growing a β-BPBO single crystal is obtained.
BPBO hydrate from the mixed aqueous solution
And then wash the hydrate thoroughly with pure water.
Later, the coprecipitated hydrate is placed in air at a temperature of 800 to 850 ° C.
Baking. By such treatment, β phase with good crystallinity
Can be obtained. And
By using this raw material, a known direct pulling method,
For example, the Czochralski method, the Bridgman method, etc.
To grow a BPBO single crystal having a β phase structure. [0012] DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.
You. (1) Barium chloride (BaClTwo・ 2HTwoO) 0.98mol and boric acid
(HThreeBOThree1 mol) and lead chloride (PbClTwo) 0.02mol and 2
Dissolved in 1 liter of water,Of the mixed aqueous solution Ba / Pb The ratio 98 /
Two And adjustAdjust the pH to 12.6 (Ba, Pb)
BTwoOFour・ 4HTwoO hydrate was coprecipitated. (2) Next, the coprecipitated product (Ba, Pb) BTwoOFour・ 4HTwoWash o
After rinsing at 850 ℃ for 3 hours, it has β phase structure
(Ba, Pb) BTwoOFourGot. After that, this firing raw material is
The pots were filled and grown in a high-frequency lifting furnace. This education
Conditions for seed rotation: 20 rpm, lifting speed: 3 mm
/ Hr, atmosphere was grown under atmospheric conditions. In addition, how to grow
The direction was the C-axis direction. As a result, diameter 10mm, length 20mm
Was grown. (3) Therefore, the single crystal was subjected to 1.06 Nd: YAG laser light.
Irradiation of light of μm, the second harmonic 0.53μm
Green light was confirmed, and the β-phase structure
It has been confirmed that the β-BPBO with
Was. [0013] [Comparative Example 1] (1) Barium chloride (BaClTwo・ 2HTwoO) 1mol and boric acid (HThree
BOThree) Dissolve 1 mol in 2 liters of water and adjust pH to 12.6
Prepare and Ba BTwoOFour・ 4HTwoO was precipitated. To 850 ° C
For 3 hours to produce a BBO having a β-phase structure. (2) 1 mol of the above-mentioned BBO is weighed, and 0.2 mol of PbO is added thereto.
Add and mix well in a mortar. Put this raw material in a platinum crucible
Filled and grown in a high frequency pulling furnace. This growth condition
Is a seed rotation speed: 20 rpm, a lifting speed: 3 mm / hr,
The atmosphere went in the air. Also, the growing direction is C-axis raising.
And (3) However, the lifting conditions are the same as in the above embodiment.
Nevertheless, the crystal that is pulled up has nonlinear optical
Only the active alpha phase was obtained. [0014] [Comparative Example 2] Under basically the same conditions as in the example, BaClTwo
・ 2HTwoO 0.93 mol, boric acid (HThreeBOThree) 1mol lead chloride (Pb
ClTwo) 0.07 mol, and the Ba / Pb ratio of the mixed aqueous solution is 93/7.
Was. As a result, the crystals are colored yellow and used as optical crystals.
Could not be used. [0015] Comparative Example 3 Under the same conditions as those of the embodiment,
In, BaClTwo・ 2HTwoO 0.995mol, boric acid (HThreeBOThree) 1 mol,
Lead chloride (PbClTwo) 0.005mol, and the Ba / Pb ratio of the mixed aqueous solution is
99.5 / 0.5. As a result, the obtained Pb-containing β-BB
Regarding O, no improvement in non-linear characteristics was observed. [0016] As described above, according to the present invention,
Mixing Pb with BBO by direct pulling method without flux
When growing inserted β-BPBO single crystals, nonlinear optics
BPBO single crystal with β-phase structure
Can be cultivated.

───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭63−206393(JP,A) 特開 平2−172892(JP,A) 特開 平3−54112(JP,A) 特開 平4−107431(JP,A) 特開 平4−171781(JP,A) 特開 平6−265949(JP,A) 特開 平6−289445(JP,A) (58)調査した分野(Int.Cl.7,DB名) C30B 1/00 - 35/00 CA(STN) JSTPlus(JOIS) WPI(DIALOG)──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-206393 (JP, A) JP-A-2-172892 (JP, A) JP-A-3-54112 (JP, A) JP-A-4- 107431 (JP, A) JP-A-4-171781 (JP, A) JP-A-6-265949 (JP, A) JP-A-6-289445 (JP, A) (58) Fields investigated (Int. 7 , DB name) C30B 1/00-35/00 CA (STN) JSTPlus (JOIS) WPI (DIALOG)

Claims (1)

(57)【特許請求の範囲】 【請求項1】鉛を混入させたベータ・バリウムボレイト
(β−(Ba、Pb)B2O4)単結晶を融液から直接引き上げ
法で育成するに当たって、ほう酸、塩化バリウムおよび
塩化鉛の混合水溶液を、BaイオンとPbイオンの比が
95/5〜99/1の範囲となるように調整し、その混
合水溶液からPb含有バリウムボレイト水和物((Ba、P
b) B2O4・4H2O )を沈澱させ、この沈澱物を焼成して
単結晶育成原料((Ba、Pb) B2O4)として結晶の育成
を図ることを特徴とするPb含有β−BBO単結晶の育成
方法。
(57) [Claims] [Claim 1] In growing a beta-barium borate (β- (Ba, Pb) B 2 O 4 ) single crystal mixed with lead directly from a melt by a pulling method. , Boric acid, barium chloride and lead chloride mixed aqueous solution , the ratio of Ba ion to Pb ion is
Adjust so as to be in the range of 95/5 to 99/1, and mix
Pb-containing barium borate hydrate from engagement aqueous ((Ba, P
b) Precipitate B 2 O 4 .4H 2 O) and calcine the precipitate to grow crystals as a single crystal growing raw material ((Ba, Pb) B 2 O 4 ). A method for growing a β-BBO single crystal.
JP23804093A 1993-09-24 1993-09-24 Method for growing Pb-containing β-BBO single crystal Expired - Lifetime JP3492398B2 (en)

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Application Number Priority Date Filing Date Title
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JPH0789796A JPH0789796A (en) 1995-04-04
JP3492398B2 true JP3492398B2 (en) 2004-02-03

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Publication number Priority date Publication date Assignee Title
CN100362144C (en) * 2003-02-13 2008-01-16 独立行政法人科学技术振兴机构 Method for preparing borate-based crystal and laser oscillation apparatus
TWI271384B (en) 2003-02-13 2007-01-21 Japan Science & Tech Agency Manufacture for boric acid crystals and laser oscillation apparatus
EP1667791A1 (en) * 2003-10-06 2006-06-14 Solvias AG Process for the parallel detection of crystalline forms of molecular solids
CN104532350B (en) * 2014-12-24 2017-10-27 中国科学院合肥物质科学研究院 Mix Pb2+Ion at high temperature phase barium metaborate crystal and its growing method and purposes

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