JPH0751480B2 - Method for growing lanthanum hexaboride single crystal - Google Patents
Method for growing lanthanum hexaboride single crystalInfo
- Publication number
- JPH0751480B2 JPH0751480B2 JP3204837A JP20483791A JPH0751480B2 JP H0751480 B2 JPH0751480 B2 JP H0751480B2 JP 3204837 A JP3204837 A JP 3204837A JP 20483791 A JP20483791 A JP 20483791A JP H0751480 B2 JPH0751480 B2 JP H0751480B2
- Authority
- JP
- Japan
- Prior art keywords
- single crystal
- zone
- lanthanum
- growth
- growing
- 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 - Lifetime
Links
- 239000013078 crystal Substances 0.000 title claims description 52
- 229910052746 lanthanum Inorganic materials 0.000 title claims description 25
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 title claims description 25
- 238000000034 method Methods 0.000 title claims description 21
- 239000000155 melt Substances 0.000 claims description 17
- 239000000203 mixture Substances 0.000 claims description 15
- 239000002994 raw material Substances 0.000 claims description 11
- 238000010438 heat treatment Methods 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- 230000007547 defect Effects 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000000428 dust Substances 0.000 description 3
- 230000008020 evaporation Effects 0.000 description 3
- 238000001704 evaporation Methods 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- DSSYKIVIOFKYAU-XCBNKYQSSA-N (R)-camphor Chemical compound C1C[C@@]2(C)C(=O)C[C@@H]1C2(C)C DSSYKIVIOFKYAU-XCBNKYQSSA-N 0.000 description 2
- 241000723346 Cinnamomum camphora Species 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 229960000846 camphor Drugs 0.000 description 2
- 229930008380 camphor Natural products 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000004927 fusion Effects 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 210000003041 ligament Anatomy 0.000 description 2
- 230000008646 thermal stress Effects 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000007716 flux method Methods 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Landscapes
- Solid Thermionic Cathode (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、フローティング・ゾー
ン（ＦＺ）法によるホウ化ランタン（ＬａＢ６）単結晶
の育成法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for growing a lanthanum boride (LaB 6 ) single crystal by a floating zone (FZ) method.
【０００２】[0002]
【従来の技術及び発明が解決しようとする課題】ホウ化
ランタン単結晶は、現在、寿命の長い高輝度電子放射材
料として、走査型電子顕微鏡や電子描画装置などに利用
されている。この電子放射材料として用いる場合、純度
の高い高品質単結晶が必要である。2. Description of the Related Art Lanthanum boride single crystal is currently used as a high-brightness electron emitting material having a long life in a scanning electron microscope, an electron drawing apparatus and the like. When used as this electron emitting material, a high quality single crystal with high purity is required.
【０００３】高純度なホウ化ランタン単結晶の育成法と
しては、育成温度が高く、不純物が蒸発により除去され
るフローティング・ゾーン（ＦＺ）法が適している。し
かしながら、ＦＺ法により育成された単結晶中には多く
の欠陥（例えば、粒界密度で４００ｃｍ／ｃｍ２）が存
在するという欠点があった。このため、高品質な部分を
選び、電子放射材として使用せざるを得ないのが実情で
ある。As a method for growing a high-purity lanthanum boride single crystal, a floating zone (FZ) method, which has a high growth temperature and removes impurities by evaporation, is suitable. However, there is a defect that many defects (for example, a grain boundary density of 400 cm / cm 2 ) are present in the single crystal grown by the FZ method. Therefore, in reality, it is unavoidable to select a high quality portion and use it as an electron emitting material.
【０００４】本発明は、上記従来技術の欠点を解消し
て、欠陥の少ない良質なホウ化ランタン単結晶を得る方
法を提供することを目的とするものである。It is an object of the present invention to solve the above-mentioned drawbacks of the prior art and to provide a method for obtaining a good quality lanthanum boride single crystal with few defects.
【０００５】[0005]
【課題を解決するための手段】前記課題を解決するた
め、本発明者らは、従来のＦＺ法において結晶中に粒界
を生じさせている要因を調べた結果、次のことが判明し
た。In order to solve the above problems, the inventors of the present invention have investigated the factors causing the grain boundaries in the crystal in the conventional FZ method, and have found the following.
【０００６】すなわち、ホウ化ランタン結晶の育成温度
が約２７００℃と高いため、育成された単結晶は非常に
高い温度勾配（約１５０℃／ｍｍ）の下を通過すること
になる。この育成後の冷却過程において発生する熱応力
により、結晶中に粒界を発生させ、結晶性の低下を招く
ことが判明した。That is, since the growth temperature of the lanthanum boride crystal is as high as about 2700 ° C., the grown single crystal passes under a very high temperature gradient (about 150 ° C./mm). It has been found that the thermal stress generated in the cooling process after the growth causes grain boundaries in the crystal, resulting in deterioration of crystallinity.
【０００７】そこで、結晶が育成後受ける熱応力を小さ
くするため、自己フラックス法により育成温度を下げ、
六ホウ化ランタン単結晶の育成をフローティング・ゾー
ン法により試みた。Therefore, in order to reduce the thermal stress that the crystal receives after growing, the growing temperature is lowered by the self-flux method,
The growth of lanthanum hexaboride single crystal was tried by the floating zone method.
【０００８】その結果、ランタンをフラックスに用いた
場合、すなわち、ある特定の条件で融帯組成をランタン
過剰にした場合、育成される六ホウ化ランタン単結晶に
粒界の含まない良質単結晶が得られるようになった。こ
れらの知見に基づき、本発明をなしたものである。As a result, when lanthanum is used for the flux, that is, when the zone composition is made lanthanum-excess under a certain specific condition, the grown lanthanum hexaboride single crystal produces a good quality single crystal containing no grain boundary. I got it. The present invention has been made based on these findings.
【０００９】すなわち、本発明は、フローティング・ゾ
ーン法により六ホウ化ランタン単結晶を育成するに際
し、原料焼結棒と初期融帯育成用の焼結棒又は種結晶と
の間にランタン塊を挾んで溶融させ、融帯組成のＢ／Ｌ
ａモル比を２．５〜３とすることにより、育成温度を低
下させて粒界のない単結晶を育成することを特徴とする
良質六ホウ化ランタン単結晶の育成法を要旨とするもの
である。That is, according to the present invention, when a lanthanum hexaboride single crystal is grown by the floating zone method, a raw material sintered rod and a sintered rod or seed crystal for growing an initial melt zone are used.
Lanthanum mass was melted by sandwiching between, the melt zone composition B / L
With 2.5-3 to a molar ratio, which summarized as to lower the growth temperature by growth method of quality lanthanum hexaboride single crystal characterized that you develop no grain boundary monocrystalline Is.
【００１０】以下に本発明を更に詳細に説明する。The present invention will be described in more detail below.
【００１１】[0011]
【００１２】本発明において用いられる装置の一例を図
１に示す。図中、１は高周波発振機、２は電源ライン、
３と４は高周波電流と陽極電圧の検出器（デジボル）、
５はコンピュータ、６は育成炉、７と７′はそれぞれ上
軸と下軸、８と８′はホールダー、９は原料棒、９′は
初期融帯形成用の焼結棒又は種結晶、１０は融帯、１１
は単結晶、１２はワークコイル、１３は上軸駆動炉、１
４は原料供給棒の半溶融部分である。An example of the apparatus used in the present invention is shown in FIG. In the figure, 1 is a high frequency oscillator, 2 is a power line,
3 and 4 are high frequency current and anode voltage detectors (Digibol),
5 is a computer, 6 is a growth furnace, 7 and 7'are upper and lower shafts, 8 and 8'are holders, 9 is a raw material rod, 9'is a sintered rod or seed crystal for forming the initial melt zone, 10 Is a ligament, 11
Is a single crystal, 12 is a work coil, 13 is an upper shaft driving furnace, 1
4 is a semi-molten portion of the raw material supply rod.
【００１３】試料の加熱は、ワークコイル１２に高周波
電流を流すことにより、試料中に誘導電流を生じさせ、
そのジュール熱により行なう。このようにして形成され
た融帯１０に上方より原料棒９を送り込み、下方より単
結晶１１を育成する。To heat the sample, a high-frequency current is passed through the work coil 12 to generate an induced current in the sample,
The Joule heat is used. The raw material rod 9 is fed into the thus-formed melt zone 10 from above, and the single crystal 11 is grown from below.
【００１４】育成中の融帯１０の形状は、融帯とワーク
コイル間の相互インピーダンス変化により検出すること
ができる。すなわち、融帯が細くなれば、インピーダン
スが低くなり、高周波電流が増加する。逆に太くなれ
ば、高周波電流が減少する。したがって、陽極電圧との
比（高周波電流／陽極電圧）をとれば、融帯が細くなる
と比の値が増加し、太くなると比の値が減少する。The shape of the melt zone 10 during growth can be detected by the change in the mutual impedance between the melt zone and the work coil. That is, as the melt zone becomes thinner, the impedance becomes lower and the high frequency current increases. On the other hand, when it becomes thicker, the high frequency current decreases. Therefore, if the ratio with the anode voltage (high-frequency current / anode voltage) is taken, the ratio value increases as the zone becomes thinner, and the ratio value decreases as the zone becomes thicker.
【００１５】したがって、高周波電流と陽極電圧を２台
のデジボル３、４により検出し、コンピュータ５におい
て、融帯形状を判断し、その結果に基づき、融帯形状が
一定になるように、育成炉の上軸７（原料棒９）の移動
速度を制御する。Therefore, the high frequency current and the anode voltage are detected by the two digibols 3 and 4, and the computer 5 determines the zone shape, and based on the result, the zone shape is kept constant. The moving speed of the upper shaft 7 (raw material rod 9) is controlled.
【００１６】この方法に従うと、育成中の融帯が一定に
保持されるため、育成される結晶の直径がスムースにな
り、手動育成に比較して再現性よく粒界の含まない単結
晶を育成するのに有効である。According to this method, since the melt zone during the growth is kept constant, the diameter of the grown crystal becomes smooth, and a single crystal having no grain boundary is grown with good reproducibility as compared with the manual growth. It is effective to do.
【００１７】次に本発明による単結晶の手順を示す。ま
ず、原料のＬａＢ６粉末に、結合剤として少量の樟脳を
加えて、ラバープレス（２０００ｋｇ／ｃｍ２）により
圧粉棒を作製する。この圧粉棒を真空中又は不活性ガス
雰囲気中で千数百℃に加熱して、原料焼結棒を作製す
る。Next, the procedure of the single crystal according to the present invention will be described. First, a small amount of camphor as a binder is added to the raw material LaB 6 powder, and a dust bar is produced by a rubber press (2000 kg / cm 2 ). This powder compact rod is heated to a few thousand and several hundred degrees Celsius in a vacuum or in an inert gas atmosphere to prepare a raw material sintered rod.
【００１８】得られた焼結棒９を上軸７にホルダー８を
介してセットし、下軸７′には、初期融帯形成用の焼結
棒又は種結晶９′をホルダー８′を介してセットする。
そし て、焼結棒９と、初期融帯形成用の焼結棒又は種結
晶９′との間には、初期融帯組成を制御するためのラン
タン金属塊を挾む。次に、Ｌａ金属とその周辺を加熱に
より溶融させ、融帯１０を形成させ、上軸７と下軸７′
をゆっくりと下方に移動させて単結晶１１を育成する。The obtained sintered rod 9 is set on the upper shaft 7 via a holder 8, and the lower rod 7'is provided with a sintered rod or seed crystal 9'for forming an initial melt zone via a holder 8 '. Set.
And in a sintered rod 9, sintered rods Further seed formation for initial melt zone formed
Between the crystal 9 ', sandwiching the lanthanum metal block for controlling the initial melt zone composition. Next, the La metal and its periphery are melted by heating to form a fusion zone 10, and the upper shaft 7 and the lower shaft 7'are formed.
Is slowly moved downward to grow the single crystal 11.
【００１９】この時、下軸７′の移動速度、すなわち、
結晶育成速度は、育成中常に一定に保持する。その範囲
は１ｃｍ／ｈ未満、より好ましくは０．２ｃｍ／ｈ以
上、１ｃｍ／ｈ未満である。結晶中に気泡が入り易いの
で、本発明では、ＬａＢ６融液からの従来の育成法に比
較して育成速度を遅く設定している。なお、上軸７の移
動速度の設定値は、原料焼結棒の密度が一般に１００％
でないため、それを補償するように下軸７の移動速度よ
り速く設定されている。この設定値を基準にして、融帯
形状の変化に伴い、上軸移動速度を速くしたり又は遅く
したり、コンピュータ制御される。At this time, the moving speed of the lower shaft 7 ', that is,
The crystal growth rate is always kept constant during the growth. The range is less than 1 cm / h, more preferably 0.2 cm / h or less
Above 1 cm / h . Since bubbles easily enter the crystal, in the present invention, the growth rate is set to be slower than the conventional growth method from the LaB 6 melt. The set value of the moving speed of the upper shaft 7 is generally 100% when the density of the raw material sintered rod is 100%.
Therefore, it is set to be higher than the moving speed of the lower shaft 7 so as to compensate for it. Based on this set value, the upper shaft moving speed is increased or decreased according to the change of the zone shape, and is computer controlled.
【００２０】雰囲気としては数気圧のアルゴン又はヘリ
ウムなどの不活性ガスが用いられる。これは、蒸発の抑
制と高周波ワークコイル部分で発生する放電を防止する
ためである。An inert gas such as argon or helium having a pressure of several atmospheres is used as the atmosphere. This is to suppress evaporation and to prevent discharge generated in the high frequency work coil portion.
【００２１】融帯組成は育成中蒸発などにより変化しな
いので、最初にセットするランタン金属塊の量のみで制
御できる。したがって、育成開始後１時間以後において
（すなわち、定常状態において）、加熱電力制御の必要
なく結晶を育成できる。この際、育成温度が低い程（す
なわち、ランタン添加量の多い程）、結晶中の粒界が少
なくなる傾向にある。Since the composition of the melt zone does not change due to evaporation or the like during the growth, it can be controlled only by the amount of the lanthanum metal mass initially set. Therefore, after 1 hour from the start of growth (that is, in a steady state), crystals can be grown without the need for heating power control. At this time, the lower the growth temperature (that is, the larger the amount of lanthanum added), the smaller the grain boundaries in the crystal.
【００２２】しかしながら、融帯中のランタン含有量が
多過ぎると、原料棒の半溶融状態部分（図１の半溶融部
分１４）における融液量が増加し、融帯保持及び溶け込
みが悪くなり、安定な育成が困難になる。その結果、再
現性よく、粒界を含まない良質結晶の育成が困難にな
る。However, if the lanthanum content in the melt zone is too high, the melt volume in the semi-molten state portion (semi-melted portion 14 in FIG. 1) of the raw material rod increases, and the melt zone retention and melting deteriorate. Stable training becomes difficult. As a result, it becomes difficult to grow a good quality crystal that does not contain grain boundaries with good reproducibility.
【００２３】結局、後述の実施例に示すように、融液組
成（Ｂ／Ｌａモル比）が３〜２．５の組成範囲で再現性
よく、粒界のない単結晶を育成することができる。[0023] Finally, as shown in the Examples below, the melt composition (B / La molar ratio) reproducibly composition range of 3 to 2.5, it is possible to grow a grain boundary-free single crystal .
【００２４】融帯中のランタン成分を過剰にする他の方
法としては、六ホウ化ランタンよりランタン過剰の原料
焼結棒を用いることが考えられるが、この場合には、融
帯中のランタン成分の増加と共に、加熱電力を下げる必
要が生じ、融帯組成の所定の安定制御は容易ではない。 [0024] As another method for an excess of lanthanum components in fusion zone, it is considered Rukoto using lanthanum excess material sintered rod than lanthanum hexaboride, in this case, lanthanum in the melt zone As the components increase, it becomes necessary to lower the heating power, and it is not easy to perform the predetermined stable control of the zone composition.
【００２５】なお、本発明の育成法は、高周波加熱以外
の加熱法、例えば、赤外線集中加熱による単結晶育成に
も適用することができる。 The growing method of the present invention can be applied to heating methods other than high-frequency heating, for example, single crystal growth by concentrated infrared heating.
【００２６】次に本発明の実施例を示す。Next, examples of the present invention will be described.
【００２７】[0027]
【実施例】市販のＬａＢ６粉末に結合剤として樟脳を少
量加えて混合した。この混合物を直径１２ｍｍのゴム袋
に詰めて円柱状にし、これを２０００ｋｇ／ｃｍ２のラ
バープレスを行なって圧粉棒を得た。この圧粉棒を真空
中、１８００℃で加熱して直径１０ｍｍ、長さ約１２ｃ
ｍ程度の焼結棒を得た。Example A small amount of camphor as a binder was added to a commercially available LaB 6 powder and mixed. This mixture was packed in a rubber bag having a diameter of 12 mm to form a columnar shape, which was subjected to a rubber press of 2000 kg / cm 2 to obtain a dust bar. This dust bar is heated at 1800 ° C. in vacuum to have a diameter of 10 mm and a length of about 12 c.
A sintered rod of about m was obtained.
【００２８】この焼結棒を図１に示すＦＺ育成炉の上軸
にホルダーを介して固定し、下軸にはＬａＢ６単結晶を
固定した。両者の間にＬａ金属を挾み、融帯組成を制御
した。育成炉に７気圧のアルゴンを充填した後、高周波
コイル（内径１４ｍｍ、３巻２段）によりＬａ金属とそ
の周辺部を溶かし、初期融帯を形成し、０．７５ｃｍ／
ｈの速度で８時間下方に移動させて、＜１００＞方位に
全長６ｃｍ、直径０．８ｃｍの単結晶を育成した。The sintered rod was fixed to the upper shaft of the FZ growth furnace shown in FIG. 1 via a holder, and the LaB 6 single crystal was fixed to the lower shaft. La metal was sandwiched between the two to control the zone composition. After filling the growth furnace with argon at 7 atm, the high frequency coil (internal diameter 14 mm, 3 windings, 2 steps) melts La metal and its peripheral portion to form an initial melt zone, 0.75 cm /
It was moved downward at a speed of h for 8 hours to grow a single crystal with a total length of 6 cm and a diameter of 0.8 cm in the <100> orientation.
【００２９】育成中の融帯形状制御は、次の要領で行な
った。すなわち、育成を開始して１時間後の安定化した
時の融帯形状を基準形伏（高周波電流／陽極電圧＝１４
１．７／４．３５）とした。上軸の移動速度制御は、
（基準速度（９ｍｍ／ｈ）＋１０×（その時点の融帯形
状−基準形状）＋１５０×（毎秒当りの融帯形状変
化））の式に従い行なった。スムースな外形を持つ単結
晶の育成に有効であった。The zone shape control during growth was performed as follows. That is, the ligament shape at the time of 1 hour after the start of growth and stabilization was set to the standard shape (high frequency current / anode voltage = 14).
1.7 / 4.35). The movement speed control of the upper axis is
(Reference speed (9 mm / h) + 10 × (zone shape at that time−reference shape) + 150 × (zone shape change per second)). It was effective in growing a single crystal with a smooth outer shape.
【００３０】単結晶の粒界密度については、結晶棒終端
部の（１００）面を切り出し、鏡面研磨した後、エッチ
ング（硝酸：水＝１：２の液で３０秒程度）して測定し
た。図２は、上記の操作による単結晶育成における融帯
の体積０．２ｃｍ２に対する初期融帯への添加ランタン
金属量（ｇ）、すなわち、融帯組成（Ｂ／Ｌａモル比）
と粒界密度（ｃｍ／ｃｍ２）の関係を示したものであ
る。この図２より明らかなように、融帯組成（Ｂ／Ｌａ
モル比）が、３〜２の範囲で粒界のない結晶が育成でき
た。ただ、２．５以下の融帯組成では、しばしば結晶始
端部が多結晶化した。このため、Ｂ／Ｌａモル比が３〜
２．５において粒界のない良質な単結晶が育成されるこ
とがわかった。また、たとえば、Ｂ／Ｌａモル比が３〜
２．５の範囲内にある融液組成２．８５における育成温
度は約２２５０℃で、従来の育成法に比較して５００℃
近く低かった。The grain boundary density of a single crystal was measured by cutting out the (100) plane at the end of the crystal rod, mirror-polishing it, and then etching it (with a solution of nitric acid: water = 1: 2 for about 30 seconds). FIG. 2 shows the amount of lanthanum metal added to the initial melt zone (g) with respect to the volume of the melt zone of 0.2 cm 2 in single crystal growth by the above operation , that is, the melt zone composition (B / La molar ratio).
Der those that shows the relationship between the grain boundary density (cm / cm 2)
It As is clear from FIG. 2 , the zone composition (B / La
A crystal having no grain boundary could be grown when the molar ratio) was in the range of 3 to 2. However, in the zone composition of 2.5 or less, the crystal starting portion was often polycrystallized. Therefore, the B / La molar ratio is 3 to
A high quality single crystal without grain boundaries can be grown at 2.5.
I understood. Further, for example, the B / La molar ratio is 3 to
The growth temperature of the melt composition 2.85 within the range of 2.5 is about 2250 ° C., which is 500 ° C. as compared with the conventional growth method.
It was low near.
【００３１】[0031]
【発明の効果】以上説明したように、本発明によれば、
欠陥のない良質なホウ化ランタン単結晶が得られる。As described above, according to the present invention,
A good quality lanthanum boride single crystal without defects can be obtained.
【図１】本発明に用いられる単結晶育成装置の一例を示
す説明図である。FIG. 1 is an explanatory diagram showing an example of a single crystal growth apparatus used in the present invention.
【図２】融帯組成（Ｂ／Ｌａモル比）と粒界密度（ｃｍ
／ｃｍ２）の関係を示す図である。FIG. 2 Melt zone composition (B / La molar ratio) and grain boundary density (cm
It is a figure which shows the relationship of / cm < 2 >).
１ 高周波発振機 ２ 電源ライン ３ 高周波電流の検出器（デジボル） ４ 陽極電圧の検出器（デジボル） ５ コンピューター ６ 単結晶育成炉 ７ 上軸 ７′ 下軸 ８ ホルダー ８′ ホルダー ９ 原料焼結棒 ９′ 種結晶又は初期融帯保持用焼結棒 １０ 融帯 １１ 単結晶 １２ ワークコイル １３ 上軸駆動部 １４ 半溶融部分 1 high frequency oscillator 2 power supply line 3 high frequency current detector (Digibol) 4 anode voltage detector (Digibol) 5 computer 6 single crystal growth furnace 7 upper shaft 7'lower shaft 8 holder 8'holder 9 raw material sintering rod 9 ′ Seed crystal or sintered rod for retaining the initial melt zone 10 Melt zone 11 Single crystal 12 Work coil 13 Upper shaft drive part 14 Semi-molten part
Claims (1)
化ランタン単結晶を育成するに際し、原料焼結棒と初期
融帯育成用の焼結棒又は種結晶の間にランタン塊を挾ん
で溶融させ、融帯組成のＢ／Ｌａモル比を２．５〜３と
して粒界のない単結晶を育成することを特徴とする良質
六ホウ化ランタン単結晶の育成法。1. When a lanthanum hexaboride single crystal is grown by the floating zone method, a raw material sintered rod and an initial stage are used.
Insert a lanthanum mass between sintered rods or seed crystals for growing the melt zone.
And the B / La molar ratio of the melt zone composition to 2.5 to 3
A method for growing a high quality lanthanum hexaboride single crystal characterized by growing a single crystal without grain boundaries .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3204837A JPH0751480B2 (en) | 1991-07-19 | 1991-07-19 | Method for growing lanthanum hexaboride single crystal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3204837A JPH0751480B2 (en) | 1991-07-19 | 1991-07-19 | Method for growing lanthanum hexaboride single crystal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0524992A JPH0524992A (en) | 1993-02-02 |
| JPH0751480B2 true JPH0751480B2 (en) | 1995-06-05 |
Family
ID=16497212
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3204837A Expired - Lifetime JPH0751480B2 (en) | 1991-07-19 | 1991-07-19 | Method for growing lanthanum hexaboride single crystal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0751480B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07115993B2 (en) * | 1992-05-18 | 1995-12-13 | 科学技術庁無機材質研究所長 | Method for growing lanthanum boride single crystal |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6086098A (en) * | 1983-10-18 | 1985-05-15 | Natl Inst For Res In Inorg Mater | Growth method of lanthanum boride single crystal |
-
1991
- 1991-07-19 JP JP3204837A patent/JPH0751480B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0524992A (en) | 1993-02-02 |
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