JPH0686358B2 - Cerium boride single crystal and its growth method - Google Patents
Cerium boride single crystal and its growth methodInfo
- Publication number
- JPH0686358B2 JPH0686358B2 JP19167290A JP19167290A JPH0686358B2 JP H0686358 B2 JPH0686358 B2 JP H0686358B2 JP 19167290 A JP19167290 A JP 19167290A JP 19167290 A JP19167290 A JP 19167290A JP H0686358 B2 JPH0686358 B2 JP H0686358B2
- Authority
- JP
- Japan
- Prior art keywords
- single crystal
- boride
- cerium
- cerium boride
- raw material
- 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 43
- 238000000034 method Methods 0.000 title claims description 38
- 229910052684 Cerium Inorganic materials 0.000 title claims description 25
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 title claims description 25
- 239000002994 raw material Substances 0.000 claims description 17
- 229910052746 lanthanum Inorganic materials 0.000 claims description 15
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 claims description 15
- 239000000155 melt Substances 0.000 claims description 11
- 239000000203 mixture Substances 0.000 claims description 5
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 claims description 4
- 239000000126 substance Substances 0.000 claims description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 2
- 229910052796 boron Inorganic materials 0.000 claims description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 claims description 2
- BCZWPKDRLPGFFZ-UHFFFAOYSA-N azanylidynecerium Chemical compound [Ce]#N BCZWPKDRLPGFFZ-UHFFFAOYSA-N 0.000 claims 1
- 239000000843 powder Substances 0.000 description 7
- 230000007547 defect Effects 0.000 description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 239000000463 material 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
- 239000000428 dust Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000008020 evaporation Effects 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- NJPPVKZQTLUDBO-UHFFFAOYSA-N novaluron Chemical compound C1=C(Cl)C(OC(F)(F)C(OC(F)(F)F)F)=CC=C1NC(=O)NC(=O)C1=C(F)C=CC=C1F NJPPVKZQTLUDBO-UHFFFAOYSA-N 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 230000004927 fusion Effects 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
- 230000006698 induction Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Crystals, And After-Treatments Of Crystals (AREA)
- Solid Thermionic Cathode (AREA)
Description
【発明の詳細な説明】 (産業上の利用分野) 本発明は融液法による硼化セリウム(CeB6)系単結晶と
その育成法に関する。TECHNICAL FIELD The present invention relates to a cerium boride (CeB 6 ) based single crystal by a melt method and a growing method thereof.
(従来の技術及び解決しようとする課題) 硼化セリウム単結晶は、現在、寿命の長い高輝度電子放
射材料として、有望視されている。(Prior Art and Problems to be Solved) Cerium boride single crystals are currently regarded as promising as a high-brightness electron emitting material having a long life.
硼化セリウム単結晶の育成法としては、溶液法、気相
法、融液法などが知られているが、高純度な単結晶を育
成するには、育成温度が高い融液法が適している。As a method of growing a cerium boride single crystal, a solution method, a vapor phase method, a melt method, etc. are known, but a high growth temperature melt method is suitable for growing a high-purity single crystal. There is.
融液法としては、アークベルヌーイ法、フローティング
・ゾーン法、ペデェスタル法があるが、高品質単結晶を
育成するにはフローティング・ゾーン法が適している。The melt method includes the Arc Bernoulli method, the floating zone method, and the pedestal method, but the floating zone method is suitable for growing high-quality single crystals.
従来、融液法による硼化セリウム単結晶の育成法におい
ては、単結晶の純度を高くするために、高純度の硼化セ
リウム原料が用いられてきた。しかし、この方法により
育成された単結晶中には多くの欠陥(例えば、粒界密度
で600cm/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。Conventionally, in the method for growing a cerium boride single crystal by the melt method, a high-purity cerium boride raw material has been used in order to increase the purity of the single crystal. However, there is a defect that many defects (for example, 600 cm / cm 2 in grain boundary density) are present in the single crystal grown by this method. Therefore, in reality, it is unavoidable to select a high quality portion and use it as an electron emitting material.
本発明は、上記従来技術の欠点を解消して、欠陥のない
良質な硼化セリウム単結晶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 good quality cerium boride single crystal free of defects.
(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、従来の融液法
において高純度の硼化セリウム原料を用いても単結晶中
に多くの欠陥が存在することに鑑みて、原料として、硼
化セリウム以外の材料を含有させることについて試み
た。その結果、硼化セリウムに、硼化セリウムに劣らな
い電子放射特性を示す硼化ランタンを含有させた原料を
使用したところ、硼化セリウムの電子放射特性を劣化す
ることなく、良質の硼化セリウム系単結晶が育成できる
ことを見い出した。特に、直径1cmの単結晶を育成する
場合、30モル%以上の硼化ランタンを含有させると、全
く粒界を含まない完全性の高い単結晶を育成できること
を知見し、ここに本発明をなしたものである。(Means for Solving the Problems) In order to solve the above problems, the present inventors have found that many defects exist in a single crystal even when a high-purity cerium boride raw material is used in a conventional melt method. In view of the above, an attempt was made to contain a material other than cerium boride as a raw material. As a result, when a raw material containing lanthanum boride showing electron emission characteristics not inferior to cerium boride was used for cerium boride, good cerium boride was obtained without deteriorating the electron emission characteristics of cerium boride. It has been found that a system single crystal can be grown. In particular, in the case of growing a single crystal having a diameter of 1 cm, it was found that, by containing 30 mol% or more of lanthanum boride, it is possible to grow a highly complete single crystal containing no grain boundary, and the present invention is here It was done.
すなわち、本発明は、化学式(Ce1-XLaX)B6(但し、0.
01≦x≦0.50)を有することを特徴とする硼化セリウム
系単結晶を要旨とするものである。That is, the present invention is represented by the chemical formula (Ce 1-X La X ) B 6 (provided that 0.
The essence is a cerium boride-based single crystal characterized by having 01 ≦ x ≦ 0.50).
また、その育成法は、硼化セリウム系単結晶を融液法に
よって育成するに際し、原料として、1モル%以上50モ
ル%未満の硼化ランタンを含有する硼化セリウムを使用
することを特徴とするものである。Further, the growing method is characterized in that, when growing a cerium boride-based single crystal by a melt method, cerium boride containing 1 mol% or more and less than 50 mol% lanthanum boride is used as a raw material. To do.
以下に本発明を更に詳述する。The present invention will be described in more detail below.
(作用) 本発明において用いられる単結晶育成法は融液法であ
り、前述の如く種々の方法が可能であるが、フローティ
ング・ゾーン法(以下、「FZ法」という)は、大型で高
品位の単結晶が育成し易いので、好ましい。(Operation) The single crystal growing method used in the present invention is a melt method, and various methods are possible as described above, but the floating zone method (hereinafter, referred to as “FZ method”) is a large-scale and high-quality method. Is preferable because it easily grows.
第1図はFZ法育成炉の概念図であり、1は上軸、1′は
下軸、2、2′はホルダー、3は焼結棒(原料)、3′
は初期融帯保持用焼結棒又は種結晶、4は育成した単結
晶、5は融帯、6は高周波ワークコイルである。Fig. 1 is a conceptual diagram of the FZ growth reactor, where 1 is an upper shaft, 1'is a lower shaft, 2'is a holder, 3 is a sintered rod (raw material), 3 '.
Is a sintered rod or seed crystal for holding the initial melt zone, 4 is a grown single crystal, 5 is a melt zone, and 6 is a high-frequency work coil.
原料としては、硼化セリウム粉末に硼化ランタン粉末を
1モル%以上50モル%未満混合し、これに結合剤として
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。As a raw material, lanthanum boride powder was mixed with cerium boride powder in an amount of 1 mol% or more and less than 50 mol%, and a small amount of camphor was added as a binder to the powder, and a powder pressing rod was applied with a rubber press (2000 kg / cm 2 ). Create. 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.
なお、原料焼結棒としては、上記の如く硼化ランタン粉
末を使用する以外に、ランタンの酸化物、水酸化物、塩
化物などと硼素を、硼化ランタン換算で上記所定量を含
有させることも可能である。As the raw material sintered rod, in addition to using the lanthanum boride powder as described above, lanthanum oxide, hydroxide, chloride, etc. and boron should be contained in the above predetermined amounts in terms of lanthanum boride. Is also possible.
得られた原料焼結棒3を上軸1にホルダー2を介してセ
ットし、下軸1′には、初期融帯保持用の焼結棒又は種
結晶3′をホルダー2′を介してセットする。次に原料
焼結棒3の下端を高周波ワークコイル6からの誘導加熱
により溶融させ、融帯5を形成させ、上軸1と下軸1′
をゆっくり下方に移動させて単結晶4を育成する。The obtained raw material sintered rod 3 is set on the upper shaft 1 via the holder 2, and the lower rod 1'is set on the lower shaft 1'with the sintered rod or seed crystal 3'for holding the initial zone through the holder 2 '. To do. Next, the lower end of the raw material sintering rod 3 is melted by induction heating from the high frequency work coil 6 to form a fusion zone 5, and the upper shaft 1 and the lower shaft 1 '
Is slowly moved downward to grow the single crystal 4.
その時の育成速度は0.2〜5cm/h、好ましくは0.5〜2cm/h
である。雰囲気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。The growth rate at that time is 0.2-5 cm / h, preferably 0.5-2 cm / h
Is. As the atmosphere, an inert gas such as argon or helium having a pressure of several atmospheres is used. This is to suppress evaporation and to prevent discharge generated in the high frequency work coil portion.
かくして育成される単結晶は、化学式(Ce1-XLaX)B
6(但し、0.01≦x≦0.50)を有する硼化セリウム系単
結晶である。ここで、xが0.01未満では硼化ランタンを
添加した効果が殆ど見られない。すなわち、単結晶中の
粒界密度の減少が実験誤差の中に含まれてしまう程度で
ある。また0.50以上では単結晶中に気泡が含有すること
があり、実用上好ましくない。The single crystal thus grown has the chemical formula (Ce 1-X La X ) B
It is a cerium boride-based single crystal having 6 (provided that 0.01 ≦ x ≦ 0.50). Here, when x is less than 0.01, the effect of adding lanthanum boride is hardly seen. That is, the decrease in the grain boundary density in the single crystal is included in the experimental error. If it is 0.50 or more, bubbles may be contained in the single crystal, which is not preferable in practical use.
融液法による育成法としては、上述の高周波加熱による
FZ法に限らず、赤外線集中加熱によるFZ法も可能であ
り、更には、FZ法以外に、融液より引き上げる引き上げ
法、アーク・ベルヌイ法、ペデスタル法も可能であり。
それぞれの方法に適した原料調整を行う。As the growth method by the melt method, the above-mentioned high frequency heating is used.
The FZ method is not limited to the FZ method, and the FZ method by infrared concentrated heating is also possible. Further, in addition to the FZ method, a pulling method of pulling from the melt, an arc-Bernui method, and a pedestal method are also possible.
Adjust the raw materials suitable for each method.
次に本発明の実施例を示す。Next, examples of the present invention will be described.
(実施例) 硼化セリウム粉末に所定比(x=0.02、0.05、0.1、0.
2、0.4)の硼化ランタン粉末を添加し混合した後、結合
剤として樟脳を少量加えて再び混合した。この混合物を
直径12mmのゴム袋に詰め円柱状にし、これを2000kg/cm2
のラバープレスして圧粉棒を得た。この圧粉棒を真空
中、1800℃で加熱して焼結棒を得た。(Example) A predetermined ratio (x = 0.02, 0.05, 0.1, 0.
2, 0.4) lanthanum boride powder was added and mixed, and then a small amount of camphor as a binder was added and mixed again. This mixture was packed in a rubber bag with a diameter of 12 mm and made into a columnar shape, which was 2000 kg / cm 2
Was pressed with a rubber to obtain a dust bar. This dust bar was heated at 1800 ° C. in vacuum to obtain a sintered bar.
この焼結棒を第1図に示すFZ育成炉の上軸にホルダーを
介して固定し、下軸には(Ce1-XLaX)B6単結晶を固定し
た。育成炉に7気圧のアルゴンを充填した後、高周波コ
イルにより原料焼結棒を下端を溶かして初期融帯を形成
し、1cm/hで下方に移動させて、<100>方位に単結晶を
育成した。This sintered rod was fixed to the upper shaft of the FZ growth furnace shown in FIG. 1 via a holder, and the (Ce 1-X La X ) B 6 single crystal was fixed to the lower shaft. After filling the growth furnace with argon at 7 atm, the high-frequency coil melts the lower end of the raw material sintering rod to form an initial melt zone, and moves it downward at 1 cm / h to grow a single crystal in the <100> orientation. did.
得られた単結晶は、直径1cm、長さ7cmであった。分析の
結果、原料焼結棒と同じ組成を持つ単結晶が育成され、
蒸発による組成変化のないことが確認できた。また、育
成された単結晶中のランタンの濃度は、始端部を除き、
全組成領域において一定となっていた。このことは、育
成後固化した融帯と結晶終端部の分析から、硼化セリウ
ムと硼化ランタンの分配係数が1に近いことが判明し、
融帯移動開始後すぐに定常状態になったためである。The obtained single crystal had a diameter of 1 cm and a length of 7 cm. As a result of the analysis, a single crystal with the same composition as the raw material sintered rod was grown,
It was confirmed that the composition did not change due to evaporation. In addition, the concentration of lanthanum in the grown single crystal, except the starting end,
It was constant in all composition areas. This is because the analysis of the melted zone and the crystal terminal portion solidified after growth revealed that the distribution coefficient of cerium boride and lanthanum boride was close to 1,
This is because the steady state was reached immediately after the start of the zone transfer.
育成した単結晶の粒界密度は、結晶終端部の(100)面
を切り出し、鏡面研磨した後、エッチング(硝酸:水=
1:3の液で2〜3分)して測定した結果、第2図に示す
ように、硼化セリウムに硼化ランタンを添加してゆくと
粒界密度が減少し、30モル%以上添加すると粒界が観察
できなくなった。単結晶中に粒界が存在しない領域は、
育成する結晶の直径に依存し、細くなる程、広くなっ
た。すなわち、15モル%の硼化ランタンを添加した試料
から直径6mmの単結晶を育成した場合、粒界が全く観察
されなかった。The grain boundary density of the grown single crystal was determined by cutting out the (100) plane at the crystal end, mirror-polishing, and then etching (nitric acid: water =
As a result of measurement with a solution of 1: 3) for 2 to 3 minutes, as shown in FIG. 2, when lanthanum boride is added to cerium boride, the grain boundary density decreases, and 30 mol% or more is added. Then the grain boundaries could not be observed. The region where no grain boundary exists in the single crystal is
It became wider as it became thinner, depending on the diameter of the grown crystal. That is, when a single crystal with a diameter of 6 mm was grown from a sample to which 15 mol% lanthanum boride was added, no grain boundary was observed.
(発明の効果) 以上詳述したとおり、本発明によれば、欠陥のない良質
な硼化セリウム系単結晶を提供することができ、敢えて
高純度硼化セリウム原料を使用しなくともよいので経済
的である。(Effects of the Invention) As described in detail above, according to the present invention, it is possible to provide a high-quality cerium boride single crystal free from defects, and it is not necessary to use a high-purity cerium boride raw material, which is economical. Target.
第1図はFZ育成炉の一例を説明する図、 第2図は実施例で得られた単結晶の粒界密度と硼化ラン
タン添加量の関係を示す図である。 1……上軸、1′……下軸、2、2′……ホルダー、3
……焼結棒(原料)、3′……初期融帯保持用焼結棒又
は種結晶、4……育成した単結晶、5……融帯、6……
高周波ワークコイル。FIG. 1 is a diagram for explaining an example of an FZ growth furnace, and FIG. 2 is a diagram showing the relationship between the grain boundary density of the single crystal obtained in the example and the amount of lanthanum boride added. 1 ... Upper shaft, 1 '... Lower shaft, 2, 2' ... Holder, 3
...... Sintered rod (raw material), 3 '... Sintered rod or seed crystal for holding the initial zone, 4 ... Grown single crystal, 5 ... Zone, 6 ...
High frequency work coil.
Claims (3)
0.50)を有することを特徴とする硼化セリウム系単結
晶。1. A chemical formula (Ce 1-X La X ) B 6 (where 0.01 ≦ x ≦
0.50) having a cerium boride single crystal.
成するに際し、原料として、1モル%以上50モル%未満
の硼化ランタンを含有する硼化セリウムを使用すること
を特徴とする硼化セリウム系単結晶の育成法。2. A cerium boride containing 1 mol% or more and less than 50 mol% lanthanum boride is used as a raw material when growing a cerium boride single crystal by a melt method. Method for growing cerium nitride single crystal.
物、水酸化物又は塩化物と硼素を所定比に混合したもの
を用いる請求項2に記載の方法。3. The method according to claim 2, wherein a mixture of lanthanum oxide, hydroxide or chloride and boron in a predetermined ratio is used instead of lanthanum boride.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19167290A JPH0686358B2 (en) | 1990-07-19 | 1990-07-19 | Cerium boride single crystal and its growth method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19167290A JPH0686358B2 (en) | 1990-07-19 | 1990-07-19 | Cerium boride single crystal and its growth method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0477398A JPH0477398A (en) | 1992-03-11 |
| JPH0686358B2 true JPH0686358B2 (en) | 1994-11-02 |
Family
ID=16278542
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19167290A Expired - Lifetime JPH0686358B2 (en) | 1990-07-19 | 1990-07-19 | Cerium boride single crystal and its growth method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0686358B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9790620B1 (en) * | 2017-01-06 | 2017-10-17 | Nuflare Technology, Inc. | Method of reducing work function in carbon coated LaB6 cathodes |
-
1990
- 1990-07-19 JP JP19167290A patent/JPH0686358B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0477398A (en) | 1992-03-11 |
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