JP2702545B2 - Method for producing bismuth germanate single crystal - Google Patents
Method for producing bismuth germanate single crystalInfo
- Publication number
- JP2702545B2 JP2702545B2 JP7461289A JP7461289A JP2702545B2 JP 2702545 B2 JP2702545 B2 JP 2702545B2 JP 7461289 A JP7461289 A JP 7461289A JP 7461289 A JP7461289 A JP 7461289A JP 2702545 B2 JP2702545 B2 JP 2702545B2
- Authority
- JP
- Japan
- Prior art keywords
- crystal
- single crystal
- melt
- temperature gradient
- bismuth germanate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Crystals, And After-Treatments Of Crystals (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は光学用、γ線シンチレータ用として有用な式
Bi4Ge3O12で示されるゲルマニウム酸ビスマス単結晶の
製造方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a formula useful for optical and γ-ray scintillators.
The present invention relates to a method for producing a bismuth germanate single crystal represented by Bi 4 Ge 3 O 12 .
〔従来の技術と解決すべき課題〕 前記ゲルマニウム酸ビスマス（Bi4Ge3O12以下BGOと略
記）単結晶は酸化ビスマス（Bi2O3）、二酸化ゲルマニ
ウム（GeO2）粉の溶融体からチヨクラルスキー法による
単結晶引き上げ法によって製造されている。しかし、こ
の方法による単結晶育成法では結晶成長過程において結
晶の固液界面における温度のゆらぎおよび不純物の蓄積
による結晶成長速度のゆらぎが起るため、結晶中に取り
込まれる液体が凝固する際に固体と液体との密度差等の
原因によるボイドが帯状に発生し、これが光の散乱体と
なり、得られる単結晶体の結晶品質と結晶化歩留りを低
下させるという不利がある。[Prior Art and Problems to be Solved] The bismuth germanate (Bi 4 Ge 3 O 12 or less, abbreviated as BGO) single crystal is prepared from a melt of bismuth oxide (Bi 2 O 3 ) and germanium dioxide (GeO 2 ) powder It is manufactured by a single crystal pulling method by the Kralski method. However, in the single crystal growth method according to this method, the temperature fluctuation at the solid-liquid interface of the crystal and the fluctuation of the crystal growth rate due to the accumulation of impurities occur during the crystal growth process. There is a disadvantage that voids are generated in a band shape due to a difference in density between the liquid crystal and the liquid, and the voids are used as light scatterers to lower the crystal quality and the crystallization yield of the obtained single crystal.
そのため、このようなボイドの発生を防止する方法が
各種提案されている。例えば引上げ時の種結晶の回転数
を40〜60rpmとし成長結晶の直径Ｄと結晶の固液界面の
凸出高さＨとの比H/Dを−0.2〜0.2の範囲となるように
調整して、固液界面の平坦化をはかりボイドの発生量を
少なくする方法（特公昭58−49517号公報）等が知られ
ているが、このような大きい回転数では、結晶の成長過
程で結晶が捩れたり、切断したりするという問題が発生
する。Therefore, various methods for preventing the generation of such voids have been proposed. For example, the rotation speed of the seed crystal at the time of pulling is set to 40 to 60 rpm, and the ratio H / D between the diameter D of the grown crystal and the protruding height H of the solid-liquid interface of the crystal is adjusted to be in the range of -0.2 to 0.2. Thus, a method of reducing the amount of voids by flattening the solid-liquid interface (Japanese Patent Publication No. 58-49517) is known. However, at such a high rotation speed, the crystal grows during the crystal growth process. Problems such as twisting and cutting occur.
本発明はこのような不利を解決したBGOの製造方法を
提供することを目的とするものである。本発明者らは酸
化ビスマスと二酸化ゲルマニウムとの融液からの単結晶
引上げ時に、種結晶の回転数を大きくしても、成長結晶
が捩れたり、切断したりしない条件について種々検討し
た結果、本発明に到達したのであって、本発明の要旨は
酸化ビスマスと二酸化ゲルマニウムの混合物またはその
焼結体の融液からチヨクラルスキー法により、BGO単結
晶を成長させるに当たり、結晶径と融液内の軸方向の温
度勾配を夫々、該結晶性をＸ軸（mm）とし、該温度勾配
をＹ軸（℃/cm）としたXY平面において点（40,5），（4
0,30），（120,110）および（120,85）に囲まれた範囲
に制御することを特徴とするゲルマニウム酸ビスマス単
結晶の製造方法にある。An object of the present invention is to provide a method for manufacturing BGO that has solved such disadvantages. The present inventors have conducted various studies on conditions under which a grown crystal is not twisted or cut even when the number of rotations of a seed crystal is increased when pulling a single crystal from a melt of bismuth oxide and germanium dioxide. Having reached the invention, the gist of the present invention is to grow a BGO single crystal from a melt of a mixture of bismuth oxide and germanium dioxide or a sintered body thereof by the Tyochralski method, the crystal diameter and the amount of The points (40,5) and (4) on the XY plane with the temperature gradient in the axial direction as the X axis (mm) and the temperature gradient as the Y axis (° C./cm), respectively.
(0, 30), (120, 110), and (120, 85).
本発明の方法において出発原料とされる酸化ビスマス
（Bi2O3）、二酸化ゲルマニウム（GeO2）はできるだけ
高純度のもの、特に純度99.99％以上のものが好ましい
が、これらはチヨクラルスキー法による単結晶引上げの
ために粉砕した酸化ビスマス（Bi2O3）と二酸化ゲルマ
ニウム（GeO2）とを当量宛混合してから1,050℃以上に
加熱して混合融液とすればよい。また、酸化ビスマスと
二酸化ゲルマニウムとを混合したのち700〜1,000℃で焼
成した焼成体を1,050℃以上に加熱して融液としてもよ
い。この融液からBGOの引上げに使用される種結晶は、
従来法で得られたBGO単結晶から切り出した5mm×5mm程
度の大きさであればよい。Bismuth oxide (Bi 2 O 3 ) and germanium dioxide (GeO 2 ) used as starting materials in the method of the present invention are preferably as pure as possible, especially those having a purity of 99.99% or more. Bismuth oxide (Bi 2 O 3 ) and germanium dioxide (GeO 2 ) pulverized for pulling a single crystal may be mixed in equivalent amounts, and then heated to 1,050 ° C. or more to form a mixed melt. Alternatively, a melt obtained by mixing bismuth oxide and germanium dioxide and then firing at 700 to 1,000 ° C. may be heated to 1,050 ° C. or higher to form a melt. The seed crystal used to pull BGO from this melt is:
The size may be about 5 mm × 5 mm cut out from the BGO single crystal obtained by the conventional method.
本発明は各BGO単結晶の結晶径における温度勾配の制
御が最も重要なポイントであって、各結晶径における融
液内の軸方向の温度勾配が第１図に示す範囲外では結晶
に捩れやボイドの混入が多くなり、結晶にクラックや切
断が発生し易くなる。したがって、本発明の効果を得る
にはこれらの条件を満足する制御が必要である。The most important point of the present invention is the control of the temperature gradient in the crystal diameter of each BGO single crystal. If the axial temperature gradient in the melt at each crystal diameter is out of the range shown in FIG. The inclusion of voids increases, and cracks and cuts easily occur in the crystal. Therefore, in order to obtain the effects of the present invention, control satisfying these conditions is necessary.
以下、実施例と比較例をあげるが、融液内の軸方向の
温度分布の測定は、融液の中心軸にそってPR熱電対を用
い、融液表面付近では5mm間隔で、通常は10mm間隔で測
定され、この測定値を用いて、融液内の軸方向の温度勾
配は次式により算出した。Hereinafter, Examples and Comparative Examples will be given, but the measurement of the temperature distribution in the axial direction in the melt is performed using a PR thermocouple along the central axis of the melt, at intervals of 5 mm near the melt surface, usually 10 mm. The temperature gradient was measured at intervals, and using this measurement value, the axial temperature gradient in the melt was calculated by the following equation.
実施例、比較例 平均粒径が50μｍである純度99.97％の酸化ビスマス
（Bi2O3）と純度99.99％の二酸化ゲルマニウム（GeO2）
とをBi4Ge3O12が32kgとなる量で混合し、これを白金ル
ツボに装入し、高周波誘導加熱を用い1,070℃に加熱溶
解させた。 Examples and Comparative Examples Bismuth oxide (Bi 2 O 3 ) having an average particle diameter of 50 μm and a purity of 99.97% and germanium dioxide (GeO 2 ) having a purity of 99.99%
And Bi 4 Ge 3 O 12 were mixed in an amount of 32 kg, and the mixture was charged into a platinum crucible and heated and dissolved at 1,070 ° C. using high-frequency induction heating.
ついでこの融液に5mm×5mmのBi4Ge3O12の種結晶を浸
漬し、回転しながら引上げを行い、Bi4Ge3O12の単結晶
を得、このBGO結晶についてボイドや捩れを評価した。
第１表にNo.1〜14の試料について育成条件と得られたBG
O結晶についての評価を示し、また第１図にその結果を
図示した。Next, a seed crystal of Bi 4 Ge 3 O 12 of 5 mm × 5 mm was immersed in this melt, pulled up while rotating, a single crystal of Bi 4 Ge 3 O 12 was obtained, and the voids and twists of this BGO crystal were evaluated. did.
Table 1 shows the growth conditions and the obtained BG for the samples Nos. 1 to 14.
The evaluation of the O crystal was shown, and the results are shown in FIG.
〔発明の効果〕 本発明は上述のとおりの構成であるので、単結晶育成
時における固液界面が平坦になり、結晶の捩れや切断が
なく、ボイドの発生も起らない。したがって本発明によ
って得られたBGO単結晶は光学用、γ線シンチレータ用
として最適である。 [Effects of the Invention] Since the present invention is configured as described above, the solid-liquid interface during the growth of a single crystal becomes flat, there is no twisting or cutting of the crystal, and no generation of voids occurs. Therefore, the BGO single crystal obtained by the present invention is most suitable for optics and γ-ray scintillator.
第１図は結晶径と融液内の軸方向の温度勾配との関係を
示すグラフである。FIG. 1 is a graph showing the relationship between the crystal diameter and the temperature gradient in the axial direction in the melt.
Claims (1)
物またはその焼結体の融液からチヨクラルスキー法によ
り、ゲルマニウム酸ビスマス単結晶を成長させるに当た
り、結晶径と融液内の軸方向の温度勾配を夫々、該結晶
径をＸ軸（mm）とし、該温度勾配をＹ軸（℃/cm）とし
たXY平面において点（40,5），（40,30），（120,110）
および（120,85）に囲まれた範囲に制御すること特徴と
するゲルマニウム酸ビスマス単結晶の製造方法。In growing a bismuth germanate single crystal from a melt of a mixture of bismuth oxide and germanium dioxide or a sintered body of the mixture by the Tjochralski method, a crystal diameter and an axial temperature gradient in the melt are determined. Points (40,5), (40,30), (120,110) on the XY plane with the crystal diameter being the X axis (mm) and the temperature gradient being the Y axis (° C./cm), respectively.
And (120, 85).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7461289A JP2702545B2 (en) | 1989-03-27 | 1989-03-27 | Method for producing bismuth germanate single crystal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7461289A JP2702545B2 (en) | 1989-03-27 | 1989-03-27 | Method for producing bismuth germanate single crystal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02252689A JPH02252689A (en) | 1990-10-11 |
| JP2702545B2 true JP2702545B2 (en) | 1998-01-21 |
Family
ID=13552172
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7461289A Expired - Fee Related JP2702545B2 (en) | 1989-03-27 | 1989-03-27 | Method for producing bismuth germanate single crystal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2702545B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110331443B (en) * | 2019-07-09 | 2021-09-03 | 同济大学 | Rare earth ion doped germanate eutectic material and preparation method thereof |
-
1989
- 1989-03-27 JP JP7461289A patent/JP2702545B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02252689A (en) | 1990-10-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101970602B1 (en) | Method for controlling gallium content in gadolinium - gallium garnet scintillators | |
| JP4193610B2 (en) | Single crystal manufacturing method | |
| US6514336B1 (en) | Method of growing piezoelectric lanthanide gallium crystals | |
| JP2702545B2 (en) | Method for producing bismuth germanate single crystal | |
| DE2162897A1 (en) | Spinel grown by the Czochralski process and the process for its manufacture | |
| WO1991011546A1 (en) | Doped crystalline compositions and a method for preparation thereof | |
| JP2795030B2 (en) | Manufacturing method of single crystal silicon rod | |
| JP2622165B2 (en) | Method for producing bismuth germanate single crystal | |
| EP0174672B1 (en) | Method of manufacturing bismuth germanate crystals | |
| JP3115145B2 (en) | Single crystal manufacturing method | |
| JP2005145742A (en) | Method for manufacturing single crystal, graphite heater, and single crystal manufacturing apparatus | |
| JP4955542B2 (en) | Oxide single crystal, method for producing the same, and single crystal wafer | |
| JPH068238B2 (en) | Method for producing single crystal bismuth germanate | |
| KR100321373B1 (en) | Method for fabricating bismuth germanium oxides crystal | |
| JP2647052B2 (en) | Method for producing rare earth vanadate single crystal | |
| JPS6126591A (en) | Crystal growing method | |
| JP2881737B2 (en) | Manufacturing method of optical single crystal | |
| JPH0367997B2 (en) | ||
| US6413442B2 (en) | Method of producing single crystal and piezoelectric element | |
| JP2741747B2 (en) | Oxide single crystal and method for producing the same | |
| JP2002193698A (en) | METHOD FOR PRODUCING ZnO SINGLE CRYSTAL | |
| JP2003137691A (en) | Method of producing single crystal | |
| JPS6270296A (en) | Production of bi24si2o40 single crystal | |
| JPS58125696A (en) | Preparation of single crystal of mn-zn ferrite | |
| JPH032838B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |