JPS6234720B2 - - Google Patents
Info
- Publication number
- JPS6234720B2 JPS6234720B2 JP56209369A JP20936981A JPS6234720B2 JP S6234720 B2 JPS6234720 B2 JP S6234720B2 JP 56209369 A JP56209369 A JP 56209369A JP 20936981 A JP20936981 A JP 20936981A JP S6234720 B2 JPS6234720 B2 JP S6234720B2
- Authority
- JP
- Japan
- Prior art keywords
- single crystal
- linbo
- voltage
- temperature
- cracks
- 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
Links
- 239000013078 crystal Substances 0.000 claims description 34
- 229910013641 LiNbO 3 Inorganic materials 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 9
- 230000005684 electric field Effects 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 4
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 claims description 3
- 230000010287 polarization Effects 0.000 description 8
- 238000010586 diagram Methods 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B33/00—After-treatment of single crystals or homogeneous polycrystalline material with defined structure
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/10—Inorganic compounds or compositions
- C30B29/16—Oxides
- C30B29/22—Complex oxides
- C30B29/30—Niobates; Vanadates; Tantalates
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Crystallography & Structural Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Inorganic Insulating Materials (AREA)
Description
（発明の技術分野）
本発明はリチウムニオベート（以下LiNbO3と
記す）単結晶の単一分域の方法に関する。
（発明の技術的背景）
LiNbO3単結晶を単一分域化することは公知で
ある。
例えばＺ軸引上げLiNbO3単結晶を単一分域化
する為には第１図に示すようにヒータ１で加熱で
きるようにした電気炉２内に引上げた単結晶３を
Ｚ面に電極４を設け、スイツチ７を投入してリー
ド線５から電圧６を加えられるようにしておく。
このときのLiNbO3単結晶の加熱曲線（実線）お
よび電圧印加特性（破線）を第２図に示す。多く
の場合単結晶の温度上昇は100℃／時間、t0からt2
までの保持温度はキユリー点Tcよりわずかに高
い1200℃、温度降下は100℃／時間である。一定
温度に保持し始める時間t0から30分後t1において
電圧1V／cmを印加し、さらに30分後t2から温度を
降下させ、t1から15時間後t3で電圧を切る。以上
の操作によりLiNbO3単結晶の単一分域化は終了
する。
（背景技術の問題点）
さてこのようにして得られる単一分極化した
LiNbO3単結晶は、分極化終了時点で単結晶のク
ラツクが観察されることがある。このクラツクの
大きさは種々様々で大きいものは長さ10cm外周面
での幅１mm程度から小さいものは肉眼でやつと見
つかる程度のものまである。数多くの実験中に発
生したクラツク発生率は約５％であつた。
単結晶に発生するクラツクは生産コスト面だけ
でなく単結晶の品質特性面からみても好ましい現
象ではなく極力減少しなければならない。
（発明の目的）
本発明は上記欠点をなくすためになされたもの
で、クラツクの少ないLiNbO3単結晶を得るため
の製造方法を提供することを目的とする。
（発明の概要）
発明者等は分極化後のクラツクを減少させるべ
く分極化の方法における種々の要因について実験
研究を行う中で単結晶の電圧印加条件もクラツク
の一原因になつていることを見出しこの発明を完
成した。
すなわち本発明はLiNbO3単結晶のＺ軸方向に
電界印加のための電極を設け、この単結晶を所定
の温度に加熱し、この所定温度において前記単結
晶に所定の電界を印加する工程を有する単結晶の
単一分域化方法において、前記所定の電界の印加
は緩やかに行うことを特徴とするLiNbO3の単一
分極化方法である。
数多くの実験によれば第３図の破線（実線は単
結晶の温度）に示す様に電圧を印加するに当り、
時間に対して傾斜を与えるように緩やかに印加す
ることによりクラツクが防止され、第２図の破線
に示すような急峻な電圧印加ではクラツクが多
い。こゝで電圧印加の緩やかさとクラツク発生率
との関係を第１表に示す。
TECHNICAL FIELD OF THE INVENTION The present invention relates to a single domain method for lithium niobate (hereinafter referred to as LiNbO 3 ) single crystal. (Technical Background of the Invention) It is known to single-domain a LiNbO 3 single crystal. For example, in order to make a Z-axis pulled LiNbO 3 single crystal into a single domain, as shown in FIG. The switch 7 is turned on so that a voltage 6 can be applied from the lead wire 5.
The heating curve (solid line) and voltage application characteristics (broken line) of the LiNbO 3 single crystal at this time are shown in FIG. In most cases, the temperature rise of single crystals is 100°C/hour, from t 0 to t 2
The holding temperature is 1200℃, slightly higher than the Curie point Tc, and the temperature drop is 100℃/hour. A voltage of 1 V/cm is applied at t 1 , 30 minutes after the time t 0 when the temperature is maintained at a constant temperature, and after another 30 minutes, the temperature is lowered from t 2 , and the voltage is turned off at t 3 , 15 hours after t 1 . With the above operations, the single domain formation of the LiNbO 3 single crystal is completed. (Problems with the background technology) Now, the single polarized
In LiNbO 3 single crystal, cracks in the single crystal may be observed at the end of polarization. The size of these cracks varies, ranging from large ones with a length of 10 cm and a width of 1 mm on the outer circumferential surface to small ones that can be easily seen with the naked eye. The crack incidence during many experiments was about 5%. Cracks occurring in single crystals are not a desirable phenomenon not only in terms of production costs but also in terms of quality characteristics of single crystals and must be reduced as much as possible. (Object of the Invention) The present invention was made to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide a manufacturing method for obtaining a LiNbO 3 single crystal with fewer cracks. (Summary of the Invention) The inventors conducted experimental research on various factors in the polarization method in order to reduce cracks after polarization, and discovered that voltage application conditions for single crystals were also a cause of cracks. Heading completed this invention. That is, the present invention includes the steps of providing an electrode for applying an electric field in the Z-axis direction of a LiNbO 3 single crystal, heating this single crystal to a predetermined temperature, and applying a predetermined electric field to the single crystal at this predetermined temperature. In the method for single-domaining single crystal, the method for single-polarizing LiNbO 3 is characterized in that the predetermined electric field is applied slowly. According to numerous experiments, when applying a voltage, as shown by the broken line in Figure 3 (the solid line is the temperature of the single crystal),
Cracks can be prevented by applying the voltage gradually so as to give a slope with respect to time, and if the voltage is applied steeply as shown by the broken line in FIG. 2, many cracks occur. Table 1 shows the relationship between the gradualness of voltage application and the crack occurrence rate.
【表】
（単結晶長さ10cm、単結晶の温度1200℃）
この表に示す通り電圧の印加が緩やかであれば
クラツク発生率が小さく電圧印加条件が15V／分
を越えるとクラツクが多発し、10V／分以下では
非常にクラツクが少ない。
（発明の実施例）
以下実施例により本発明を説明する。
実施例 １
第１図に示すように直径65mmの128゜Ｙカツト
LiNbO3単結晶のＺ軸方向に電極４を設け、電気
炉２内に挿入し、1200℃まで加熱する。その後、
スイツチ７を入れ、電圧６を10V／分の割合で
徐々に昇圧し、10Vになるまで昇圧を続ける。
1200℃10Vの条件で30分間の処理を行つた後100
℃／時間で降温させる。このようにしてｎ＝800
個の単一分極化処理を行つたところ４個がクラツ
クしていた。
実施例 ２
実施例１と同様に65mmの128゜ＹカツトLiNbO3
単結晶のＺ軸方向に電極４を設け、電気炉２内に
挿入し1200℃まで加熱する。その後スイツチ７を
入れ電圧６を2V／分の割合で昇上し、10Vになる
まで昇圧を続ける。1200℃10Vの条件で30分間の
処理を行つた後100℃／時間で降温させる。この
ようにしてｎ＝600個の単一分極化処理を行つた
ところ１個がクラツクしていた。
（発明の効果）
以上説明した通り、本発明はLiNbO3単結晶の
単一分極化方法において単極結晶に印加する電界
を緩やかに行うことに特徴を有するもので、本発
明によれば分極化処理における単結晶のクラツク
が大幅に減少する。[Table] (Single crystal length 10cm, single crystal temperature 1200℃) As shown in this table, if the voltage application is gentle, the crack occurrence rate is small, but if the voltage application condition exceeds 15V/min, cracks occur frequently. There are very few cracks below 10V/min. (Examples of the Invention) The present invention will be explained below with reference to Examples. Example 1 A 128° Y cut with a diameter of 65 mm as shown in Figure 1.
An electrode 4 is provided in the Z-axis direction of the LiNbO 3 single crystal, inserted into an electric furnace 2, and heated to 1200°C. after that,
Turn on switch 7 and gradually increase voltage 6 at a rate of 10V/minute, continuing to increase the voltage until it reaches 10V.
100 after processing for 30 minutes at 1200℃ and 10V.
Lower the temperature at °C/hour. In this way n=800
When the single polarization process was performed on 4 of them, 4 of them were cracked. Example 2 Same as Example 1, 65 mm 128° Y cut LiNbO 3
An electrode 4 is provided in the Z-axis direction of the single crystal, and the single crystal is inserted into an electric furnace 2 and heated to 1200°C. After that, switch 7 is turned on and voltage 6 is increased at a rate of 2V/minute, and continues to increase until it reaches 10V. After processing for 30 minutes at 1200°C and 10V, the temperature is lowered at a rate of 100°C/hour. When n=600 single polarization processes were performed in this way, one cracked. (Effects of the Invention) As explained above, the present invention is characterized in that the electric field applied to the monopolar crystal is gentle in the single polarization method of LiNbO 3 single crystal, and according to the present invention, the polarization Single crystal cracks in processing are significantly reduced.
第１図はLiNbO3単結晶の単一分極処理を行う
装置の概略図、第２図は従来のLiNbO3単結晶の
加熱曲線及び電圧印加特性を示す図、第３図は本
発明に係るLiNbO3単結晶の電圧印加特性を説明
する図である。
Figure 1 is a schematic diagram of an apparatus for single polarization treatment of LiNbO 3 single crystal, Figure 2 is a diagram showing the heating curve and voltage application characteristics of a conventional LiNbO 3 single crystal, and Figure 3 is a diagram showing the LiNbO 3 single crystal according to the present invention. FIG . 3 is a diagram illustrating voltage application characteristics of a single crystal.
Claims (1)
印加のための電極を設け、前記単結晶を所定の温
度に加熱し、この所定温度において前記単結晶に
所定の電界を印加する工程を有する単結晶の単一
分域化方法において、前記所定の電界の印加のた
めに電圧を上昇するときの割合は１分間に15V以
下の割合であることを特徴とするリチウムニオベ
ート単結晶の単一分域化方法。1. A single crystal comprising the steps of providing a lithium niobate (LiNbO 3 ) single crystal with an electrode for applying an electric field, heating the single crystal to a predetermined temperature, and applying a predetermined electric field to the single crystal at this predetermined temperature. In the single-domaining method of lithium niobate single crystal, the rate at which the voltage is increased for application of the predetermined electric field is 15 V or less per minute. method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56209369A JPS58115096A (en) | 1981-12-25 | 1981-12-25 | Method for making lithium niobate single crystal having single domain |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56209369A JPS58115096A (en) | 1981-12-25 | 1981-12-25 | Method for making lithium niobate single crystal having single domain |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58115096A JPS58115096A (en) | 1983-07-08 |
| JPS6234720B2 true JPS6234720B2 (en) | 1987-07-28 |
Family
ID=16571787
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56209369A Granted JPS58115096A (en) | 1981-12-25 | 1981-12-25 | Method for making lithium niobate single crystal having single domain |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58115096A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006179897A (en) * | 2001-09-11 | 2006-07-06 | Sumitomo Electric Ind Ltd | Workpiece holder, susceptor for semiconductor manufacturing apparatus, and processing apparatus |
| CN113293442A (en) * | 2021-05-26 | 2021-08-24 | 焦作晶锐光电有限公司 | Novel single domain process of lithium niobate crystal |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5264697A (en) * | 1975-11-22 | 1977-05-28 | Fujitsu Ltd | Process for treating single area |
-
1981
- 1981-12-25 JP JP56209369A patent/JPS58115096A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5264697A (en) * | 1975-11-22 | 1977-05-28 | Fujitsu Ltd | Process for treating single area |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58115096A (en) | 1983-07-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111128699B (en) | Composite single crystal piezoelectric substrate film and preparation method thereof | |
| JP2022528388A (en) | How to prepare a thin layer of ferroelectric material | |
| JPS6234720B2 (en) | ||
| JPS5933559B2 (en) | Single crystal manufacturing method | |
| JPS6234718B2 (en) | ||
| JPS6234719B2 (en) | ||
| JP2019127411A (en) | Method for making single domain of lithium niobate monocrystal | |
| CN108060459A (en) | A kind of lithium tantalate substrate melanism method | |
| US2355443A (en) | Method of sealing spark plug electrodes in ceramic insulators | |
| US2413013A (en) | Method of making selenium rectifiers | |
| JP2005328499A (en) | Method for manufacturing lithium tantalate substrate for surface acoustic wave element, and its substrate | |
| US4086124A (en) | Method of polarization of a ferroelectric material | |
| JPS6217853B2 (en) | ||
| JPS6335499A (en) | Method for making single domain lithium tantalate single crystal | |
| JPH01196878A (en) | Poling of lithium tantalate single crystal | |
| JPS6335497A (en) | Method for making single domain ferroelectric single crystal | |
| JPH0218395A (en) | Method for forming single domain in lithium niobate single crystal | |
| JP2022099960A (en) | Method for manufacturing oxide single crystal, and electrode used for method for manufacturing the same | |
| JP7396183B2 (en) | Heat-resistant container used for single-segmentation treatment of oxide single crystal and method for single-segmentation treatment of oxide single crystal | |
| JPH11302100A (en) | Production of lithium niobate single crystal | |
| JPS63185900A (en) | Heat-treating method of single crystal of composite oxide ferroelectrics | |
| KR940004364B1 (en) | MAKING METHOD OF SINGLE DOMAIN LiNbO3 | |
| JPS5812227B2 (en) | Single crystal manufacturing method | |
| JPS59138391A (en) | Method for processing single crystal | |
| KR950000646B1 (en) | Surface electrode treatment of lithium tantalate single crystal |