JP4051449B2 - Method for producing transparent scandium oxide sintered body using sulfate as precursor - Google Patents
Method for producing transparent scandium oxide sintered body using sulfate as precursor Download PDFInfo
- Publication number
- JP4051449B2 JP4051449B2 JP2004026606A JP2004026606A JP4051449B2 JP 4051449 B2 JP4051449 B2 JP 4051449B2 JP 2004026606 A JP2004026606 A JP 2004026606A JP 2004026606 A JP2004026606 A JP 2004026606A JP 4051449 B2 JP4051449 B2 JP 4051449B2
- Authority
- JP
- Japan
- Prior art keywords
- scandium
- scandium oxide
- sulfate
- sintered body
- precursor
- 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
- HYXGAEYDKFCVMU-UHFFFAOYSA-N scandium oxide Chemical compound O=[Sc]O[Sc]=O HYXGAEYDKFCVMU-UHFFFAOYSA-N 0.000 title claims description 34
- 238000004519 manufacturing process Methods 0.000 title claims description 19
- 239000002243 precursor Substances 0.000 title description 9
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 title description 2
- 239000000843 powder Substances 0.000 claims description 22
- 238000000034 method Methods 0.000 claims description 12
- 238000010304 firing Methods 0.000 claims description 11
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 4
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 4
- 239000007789 gas Substances 0.000 claims description 4
- 239000011164 primary particle Substances 0.000 claims description 3
- 229910052706 scandium Inorganic materials 0.000 claims description 3
- 229910052786 argon Inorganic materials 0.000 claims description 2
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 2
- SIXSYDAISGFNSX-UHFFFAOYSA-N scandium atom Chemical compound [Sc] SIXSYDAISGFNSX-UHFFFAOYSA-N 0.000 claims description 2
- 230000003647 oxidation Effects 0.000 claims 1
- 238000007254 oxidation reaction Methods 0.000 claims 1
- 229910000346 scandium sulfate Inorganic materials 0.000 description 20
- QHYMYKHVGWATOS-UHFFFAOYSA-H scandium(3+);trisulfate Chemical compound [Sc+3].[Sc+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O QHYMYKHVGWATOS-UHFFFAOYSA-H 0.000 description 20
- 238000001354 calcination Methods 0.000 description 10
- 239000013078 crystal Substances 0.000 description 8
- 239000011148 porous material Substances 0.000 description 7
- 238000005245 sintering Methods 0.000 description 7
- 239000012535 impurity Substances 0.000 description 6
- 239000002245 particle Substances 0.000 description 6
- 239000006104 solid solution Substances 0.000 description 5
- 239000000463 material Substances 0.000 description 4
- 239000002244 precipitate Substances 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 150000001875 compounds Chemical class 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- -1 scandium ions Chemical class 0.000 description 3
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 2
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 2
- 235000011130 ammonium sulphate Nutrition 0.000 description 2
- 238000000149 argon plasma sintering Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000000280 densification Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000007731 hot pressing Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000005204 segregation Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 230000002194 synthesizing effect Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 229910052729 chemical element Inorganic materials 0.000 description 1
- 239000000084 colloidal system Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 230000008034 disappearance Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- JEGUKCSWCFPDGT-UHFFFAOYSA-N h2o hydrate Chemical compound O.O JEGUKCSWCFPDGT-UHFFFAOYSA-N 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000002706 hydrostatic effect 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
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- SIWVEOZUMHYXCS-UHFFFAOYSA-N oxo(oxoyttriooxy)yttrium Chemical compound O=[Y]O[Y]=O SIWVEOZUMHYXCS-UHFFFAOYSA-N 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 150000003325 scandium Chemical class 0.000 description 1
- CAKRPOQJQRDOIT-UHFFFAOYSA-N scandium sulfuric acid Chemical compound [Sc].S(O)(O)(=O)=O CAKRPOQJQRDOIT-UHFFFAOYSA-N 0.000 description 1
- DFCYEXJMCFQPPA-UHFFFAOYSA-N scandium(3+);trinitrate Chemical compound [Sc+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O DFCYEXJMCFQPPA-UHFFFAOYSA-N 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 238000001308 synthesis method Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Images
Landscapes
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Description
この発明は、硫酸スカンジウムを熱分解して一次粒子が個々に分離していて粒度分布が
そろった微細酸化スカンジウム粉末の製造と該粉末を用いた透明焼結体の製造に関するも
のである。
The present invention relates to the production of fine scandium oxide powder in which scandium sulfate is thermally decomposed to separate primary particles and the particle size distribution is uniform, and to the production of a transparent sintered body using the powder.
さらに詳しくは、この発明は、透明焼結体製造用の原料粉体に適した微細粉末の製造方
法と該粉末を用いて各種発光管やレーザー材料、高温用の窓などに使用可能な透明焼結体
の製造方法に関するものである。
More specifically, the present invention relates to a method for producing a fine powder suitable for a raw material powder for producing a transparent sintered body, and a transparent firing that can be used for various arc tubes, laser materials, high-temperature windows, and the like. The present invention relates to a method for producing a bonded body.
酸化スカンジウムは、その結晶構造がC-希土構造（立方晶）であるので複屈折がない。
このため、粒界での光の散乱がないので、光を散乱させる気孔や介在物等を完全に除去す
ると焼結体でも透明化できる。しかも、バンド・ギャップが5.7eVと非常に大きく、屈折
率、nH、もλ= 300nmで2.0と大きい酸化物である。さらに、融点も約2430℃と非常に高く
熱伝導度も17W/mKと大きい。これらの特性を利用して、LEDあるいは高エネルギーパルスU
Vレーザー用の光損傷防止高反射材や高エネルギーレーザー用ホスト材料、赤外線用高温
窓、放電ランプ用発光管等への利用が期待されている。
Scandium oxide has no birefringence because its crystal structure is a C-rare earth structure (cubic).
For this reason, since there is no light scattering at the grain boundary, the sintered body can be made transparent by completely removing pores, inclusions and the like that scatter light. In addition, the band gap is as large as 5.7 eV, and the refractive index and n H are also as large as 2.0 at λ = 300 nm. Furthermore, the melting point is very high at about 2430 ° C, and the thermal conductivity is as high as 17 W / mK. Using these characteristics, LED or high energy pulse U
It is expected to be used as a high-reflection material for optical damage prevention for V lasers, host materials for high-energy lasers, high-temperature windows for infrared rays, arc tubes for discharge lamps, etc.
酸化スカンジウムの優れた光学的特性から、光学材料を目指した単結晶育成に関する研
究は比較的多い。例えば、Fornasieroら（非特許文献１）はチョコラルスキー法を、Bart
aやHajekら（非特許文献２）はベルヌーイ法を、Chenら（非特許文献３）はフラックス法
等を検討している。しかしながら、結晶の大きさに制限があったり不純物の混入があり、
大きくて良質な単結晶を製造するには非常に難しかったりするなどの欠点があった。
Due to the excellent optical properties of scandium oxide, there are relatively many studies on single crystal growth aimed at optical materials. For example, Fornasiero et al. (Non-Patent Document 1) use the Choral Ski method, Bart
a and Hajek et al. (Non-Patent Document 2) are studying the Bernoulli method, and Chen et al. However, there is a limit to the size of the crystals or contamination of impurities,
There is a drawback that it is very difficult to produce a large and good quality single crystal.
一方、酸化スカンジウム粉末の製造や粉末の特性付けに関して、Sidgwick (非特許文献
４)やFierroら(非特許文献５)等の報告はあるが、その数は非常に少なく、不明なことが
多く残されている。また、透明焼結体の製造においても、長い間、Gazzarら（非特許文献
６）のホットプレス法に関する研究のみであった。
On the other hand, Sidgwick (Non-patent Document 4) and Fierro et al. (Non-patent Document 5) have reported on the production of scandium oxide powder and the characterization of the powder, but the number is very small and remains unclear. Has been. Also, in the production of transparent sintered bodies, for a long time, only research related to the hot pressing method of Gazzar et al.
近年、八木や柳谷は易焼結性の酸化イットリム粉末の製造法を応用して、酸化スカンジ
ウム透明焼結体の製造法（特許文献１）を開発した。ホットプレス法はある程度焼結性の
良好な粉末であれば、比較的容易に透明焼結体を製造できる利点がある。しかしながら、
焼成中に加圧するために、高温・高圧に耐え、さらに酸化スカンジウムと反応しない型が
必要であると同時に、作業性も非常に悪いために製造できる量も限られており、材料が高
価になるという欠点があった。
In recent years, Yagi and Yanagiya have developed a method for producing a scandium oxide transparent sintered body (Patent Document 1) by applying a method for producing an easily sintered yttrium oxide powder. The hot pressing method has an advantage that a transparent sintered body can be produced relatively easily if the powder has good sintering properties to some extent. However,
In order to pressurize during firing, a mold that can withstand high temperatures and high pressures and does not react with scandium oxide is required. There was a drawback.
一方、特許文献１（特開2003-128465）では、緻密化を促進するために5wtppm以上100wt
ppm以下のAlを添加する必要があった。エントロピーから分かるように、一般に、固体の
固溶量は温度が高くなると急激に増加する。しかしながら、同発明の実施の様態の中で、
焼成温度が1800oCと非常に高くても、粒界にAlの偏析相が認められると述べている。これ
は、1400℃以上1800℃以下の焼結温度では、添加したAlの多くは粒界に偏析していたこと
を意味する。
On the other hand, in Patent Document 1 (Japanese Patent Laid-Open No. 2003-128465), in order to promote densification, 5 wtppm or more and 100 wt%
It was necessary to add Al below ppm. As can be seen from the entropy, in general, the amount of solid solution increases rapidly as the temperature increases. However, in the embodiment of the invention,
He states that even when the firing temperature is as high as 1800 o C, segregated phases of Al are observed at the grain boundaries. This means that at the sintering temperature of 1400 ° C. or higher and 1800 ° C. or lower, most of the added Al was segregated at the grain boundaries.
Johnsonら（非特許文献７）の報告から分かるように、添加量が微量でも偏析層中のAl
量は濃縮されているはずである。このために、例え添加したAl量が微量でも、焼結体の実
際の性質はAlが濃縮した偏析層の性質に支配されるという欠点がある。本発明者らは塩基
性硫酸アンモニウムを前駆体とした易焼結性酸化スカンジウム粉末の合成法と該粉末を用
いた透明酸化スカンジウム焼結体の製造法を開発（特願2003-379479）した。この発明（
特願2003-379479）の方法は透明焼結体の製造には適している。しかしながら、塩基性硫
酸スカンジウムは過飽和状態になりやすく、スカンジウムイオンを完全に沈殿させること
が難しい。このため、収率が低下するという欠点があった。
The amount should be concentrated. For this reason, even if the amount of Al added is very small, the actual properties of the sintered body have the disadvantage of being governed by the properties of the segregation layer enriched with Al. The present inventors have developed a method for synthesizing easily sinterable scandium oxide powder using basic ammonium sulfate as a precursor and a method for producing a transparent scandium oxide sintered body using the powder (Japanese Patent Application No. 2003-379479). This invention (
The method of Japanese Patent Application 2003-379479) is suitable for the production of a transparent sintered body. However, basic scandium sulfate tends to be supersaturated, and it is difficult to completely precipitate scandium ions. For this reason, there existed a fault that a yield fell.
本発明は、（１）工業的に実用可能な手法により、焼結性に優れた酸化スカンジウム粉
末の製造法と、（２）該酸化スカンジウム粉末を用いて可視部から赤外領域に渡って良好
な透光性を示す酸化スカンジウム焼結体の製造方法を提供することを目的とする。
The present invention is (1) a method for producing scandium oxide powder excellent in sinterability by a technique that can be practically used in industry, and (2) good from the visible region to the infrared region using the scandium oxide powder. An object of the present invention is to provide a method for producing a scandium oxide sintered body exhibiting excellent translucency.
本発明の易焼結性酸化スカンジウム粉末の製造法は、（ １ ）硫酸スカンジウムを1 0 0 0 ℃ 〜 1 3 0 0℃ の温度範囲で仮焼して、一次粒子径が1 0 n m〜 3 0 0 n mの酸化スカンジウムの易焼結性粉末を製造することを特徴としている。
This onset Ming sinterability scandium oxide powder manufacturing methods, (1) sulfuric acid scandium and calcined at a temperature range of 1 0 0 0 ℃ ~ 1 3 0 0 ℃, primary particle size of 1 0 nm to It is characterized by producing a 300 nm easily sinterable powder of scandium oxide.
さらに、上記（ １ ） の方法で調製した易焼結性酸化スカンジウム粉末を用いて成形体を作製し、窒素ガス等の酸化スカンジウム内を実質的に拡散できないガスの分圧が0 . 0 3MPa以下の雰囲気で焼成することを特徴としている。
Furthermore, a compact is produced using the easily sinterable scandium oxide powder prepared by the method of (1) above, and the partial pressure of a gas that cannot substantially diffuse in scandium oxide such as nitrogen gas is 0.03 MPa . It is characterized by firing in the following atmosphere.
この発明においては、上記の方法により、溶液反応を応用した易焼結性酸化スカンジウ
ム粉末の製造ばかりでなく、該粉末を用いて普通焼結法で透明酸化スカンジウム焼結体を
経済的に製造することが可能になる。
In the present invention, by the above-described method, not only the easily sinterable scandium oxide powder applying the solution reaction is manufactured, but also the transparent scandium oxide sintered body is economically manufactured using the powder by the ordinary sintering method. It becomes possible.
＜Ａ＞本発明に適する硫酸スカンジウム
本発明における硫酸スカンジウムは、結晶構造が六方晶で、Sc2 (SO4) 3・nH2O(n= 6〜
10)の化学式で記述できる化合物である。硫酸イオンを含んだ化合物であるという点では
、透明な酸化スカンジウム焼結体の製造（特願2003-379479）に好ましい前駆体の一つで
ある塩基性硫酸スカンジウム(Sc(OH)SO4・2H2O)に一致している。塩基性硫酸スカンジウ
ムの結晶構造に関する報告は無いので、結晶学的な類似性は判断できない。しかしながら
、塩基性硫酸スカンジウムはスカンジウム塩と硫酸アンモニウムの水溶液反応で沈殿とし
て取り出す化合物である。これに対して、硫酸スカンジウムは硫酸スカンジウム水溶液を
単に加熱して水分を蒸発・除去して製造する化学物質であり合成法は本質的に異なる。
<A> Scandium sulfate suitable for the present invention
The scandium sulfate in the present invention has a hexagonal crystal structure, Sc 2 (SO 4 ) 3 · nH 2 O (n = 6 to
It can be described by the chemical formula of 10). In terms of the compound containing sulfate ions, basic scandium sulfate (Sc (OH) SO 4 · 2H), which is one of the preferred precursors for the production of transparent scandium oxide sintered bodies (Japanese Patent Application 2003-379479) 2 O). Since there is no report on the crystal structure of basic scandium sulfate, the crystallographic similarity cannot be judged. However, basic scandium sulfate is a compound extracted as a precipitate by an aqueous solution reaction of a scandium salt and ammonium sulfate. In contrast, scandium sulfate is a chemical substance produced by simply heating an aqueous scandium sulfate solution to evaporate and remove moisture, and the synthesis method is essentially different.
本発明において、硫酸スカンジウムの形態は仮焼により完全に破壊され、仮焼後に出現
する酸化スカンジウム粒子の集合状態は、原料母塩である硫酸スカンジウムの結晶方位と
は無関係である。このため、硫酸スカンジウムの製造法に限定されることなく硫酸スカン
ジウムから本発明の特徴を発揮する易焼結性酸化スカンジウム粉末を製造できる。
In the present invention, the form of scandium sulfate is completely destroyed by calcination, and the aggregated state of scandium oxide particles appearing after calcination is independent of the crystal orientation of scandium sulfate, which is the raw material mother salt. For this reason, it is not limited to the manufacturing method of a scandium sulfate, The easily sinterable scandium oxide powder which exhibits the characteristic of this invention can be manufactured from a scandium sulfate.
本発明において、硫酸スカンジウムに含まれる不純物の許容量は酸化スカンジウムへの
固溶の難易度で異なる。酸化スカンジウムへの固溶が非常に少ない不純物は、光の散乱源
となる介在物を焼結体に析出するので、それらの不純物の総量は0.1モル%以下に制限する
必要がある。一方、無色で固溶する不純物は固溶限度内であれば透光性に殆ど影響しない
ので、必ずしも除去する必要はない。
In the present invention, the allowable amount of impurities contained in scandium sulfate varies depending on the degree of difficulty of solid solution in scandium oxide. Impurities with very little solid solution in scandium oxide precipitate inclusions that become light scattering sources in the sintered body, so the total amount of these impurities must be limited to 0.1 mol% or less. On the other hand, impurities that are colorless and have a solid solution hardly affect the light-transmitting property as long as they are within the solid solution limit, and thus do not necessarily need to be removed.
＜B＞仮焼
本発明において、硫酸スカンジウムは1000℃から1300℃の温度範囲で仮焼する必要があ
る。仮焼温度が低く仮焼時間が短いと、仮焼した酸化スカンジウムに硫黄分が無視できな
いほど残留し、焼結性を低下させるという欠点がある。このため、1000℃以上1150℃以下
の温度範囲で仮焼する場合、長時間仮焼する必要がある。1000℃では12時間以上、1100℃
では2時間以上仮焼する必要がある。仮焼温度が1200℃では仮焼時間に関わらずに透明焼
結体を製造できる。
<B> Calcination
In the present invention, scandium sulfate needs to be calcined in a temperature range of 1000 ° C to 1300 ° C. If the calcining temperature is low and the calcining time is short, the calcined scandium oxide has a disadvantage that the sulfur content remains so that it cannot be ignored and the sinterability is lowered. For this reason, when calcining in a temperature range of 1000 ° C. or higher and 1150 ° C. or lower, it is necessary to perform calcining for a long time. More than 12 hours at 1000 ℃, 1100 ℃
Then it is necessary to calcine for more than 2 hours. When the calcining temperature is 1200 ° C., a transparent sintered body can be produced regardless of the calcining time.
＜C＞ 焼結温度
本発明においては、透明焼結体を製造するには、1600℃以上で焼成する必要がある。16
00℃以下であると、気孔を完全に取り除くことができない。良好な透明体や耐食性に優れ
た焼結体を得るという視点では、一般に粒径が大きいほど好ましいので、焼結温度は高い
ほど好ましい。しかしながら、焼成温度が2000℃以上になると特別な焼成炉が必要になり
、加熱のためのエネルギーも急激に大きくなり、コスト高になるのという欠点がある。透
明度と同時に機械的強度が必要な場合、焼成温度を高くすると粒成長が進行して機械的強
度などの機械的性質が悪くなるので好ましくない。粒成長速度は焼結体の製造過程で混入
する微量の不純物で異なるので、製造プロセスによって異なる。特異な例を除けば、1850
℃以下で焼成することが好まし。
<C> Sintering temperature In the present invention, in order to produce a transparent sintered body, it is necessary to fire at 1600 ° C. or higher. 16
If the temperature is less than 00 ° C, the pores cannot be completely removed. From the viewpoint of obtaining a good transparent body and a sintered body excellent in corrosion resistance, a larger particle size is generally preferable, and thus a higher sintering temperature is more preferable. However, when the firing temperature is 2000 ° C. or higher, a special firing furnace is required, and there is a disadvantage that the energy for heating is rapidly increased and the cost is increased. When the mechanical strength is required simultaneously with the transparency, it is not preferable to increase the firing temperature because grain growth proceeds and mechanical properties such as mechanical strength deteriorate. The grain growth rate differs depending on the manufacturing process because it varies depending on a small amount of impurities mixed in the manufacturing process of the sintered body. 1850 except for unusual cases
It is preferable to bake below ℃.
＜D＞ 焼成雰囲気
窒素やアルゴン等の酸化スカンジウム中の拡散が困難な元素を含むガスは、気孔が孤立
すると、該気孔から焼結で取り除くことはできない。このため、焼成雰囲気として、それ
らの分圧の合計を0.03MPa以下にする必要がある。焼成雰囲気が真空であると、緻密化が
進行し気孔が孤立しても該気孔中に気孔の消滅を抑制するガスが存在しないので好ましい
。酸素イオンや水素イオンは酸化スカンジウム中を容易に拡散するので、雰囲気中に大量
の酸素ガスや水素ガスが存在しても良好な透明体を製造できる。
<D> Firing atmosphere A gas containing an element that is difficult to diffuse in scandium oxide such as nitrogen or argon cannot be removed from the pores by sintering if the pores are isolated. For this reason, it is necessary to make the total of those partial pressures 0.03 MPa or less as a firing atmosphere. It is preferable that the firing atmosphere is a vacuum because even if densification progresses and the pores are isolated, there is no gas that suppresses the disappearance of the pores in the pores. Since oxygen ions and hydrogen ions diffuse easily in scandium oxide, a good transparent body can be produced even if a large amount of oxygen gas or hydrogen gas is present in the atmosphere.
純度が99.99%の市販の酸化スカンジウムを80℃以上に保った過剰の硝酸塩水溶液で溶解
する。ホットプレート上で過剰の硝酸を除去する。合成した硝酸スカンジウムを水に溶解
しアンモニア水を加えて水酸化物の沈殿を生成させる。この水酸化物を十分に洗浄した後
に、過不足なく硫酸スカンジウムが合成できる量の硫酸溶液に分散する。水分を十分に蒸
発させて硫酸スカンジウムの結晶を合成する。合成した硫酸スカンジウムを、管状電気炉
を用いて酸素気流中、2時間仮焼して酸化スカンジウム粉末とする。
A commercially available scandium oxide having a purity of 99.99% is dissolved in an excess of an aqueous nitrate solution maintained at 80 ° C. or higher. Remove excess nitric acid on hot plate. The synthesized scandium nitrate is dissolved in water and ammonia water is added to form a hydroxide precipitate. After thoroughly washing the hydroxide, it is dispersed in a sulfuric acid solution in an amount capable of synthesizing scandium sulfate without excess or deficiency. Water is sufficiently evaporated to synthesize scandium sulfate crystals. The synthesized scandium sulfate is calcined for 2 hours in a stream of oxygen using a tubular electric furnace to obtain scandium oxide powder.
図１に、実施例１で調製した硫酸スカンジウム前駆体のＳＥＭ写真を示す。図１のSEM
写真から分かるように、スカンジウム前駆体粒子は表面が平らな0.5μm〜20.5μmの粒子
が多数集まった硬い凝集粒子を形成している。該前駆体を1200℃で仮焼すると、図２に示
すように、前駆体の形状はほぼ完全に崩壊して空隙が大きい大きさが揃った約0.08μmの
酸化スカンジウム微粒子の集合体に変化した。
In FIG. 1, the SEM photograph of the scandium sulfate precursor prepared in Example 1 is shown. SEM in Figure 1
As can be seen from the photograph, the scandium precursor particles form hard agglomerated particles in which a large number of particles having a flat surface of 0.5 μm to 20.5 μm are gathered. When the precursor was calcined at 1200 ° C., as shown in FIG. 2, the shape of the precursor almost completely collapsed and changed to an aggregate of about 0.08 μm scandium oxide fine particles with large gaps. .
1200℃で仮焼した酸化スカンジウムを200MPaの静水圧で成形した後に真空雰囲気、1700
℃で1時間焼結すると焼結密度は理論密度の99.9%であり、透光性に優れた焼結体が得られ
た。
After forming scandium oxide calcined at 1200 ° C with a hydrostatic pressure of 200MPa, vacuum atmosphere, 1700
When sintered at 1 ° C. for 1 hour, the sintered density was 99.9% of the theoretical density, and a sintered body excellent in translucency was obtained.
（ 比較例１ ）焼結を1 5 5 0℃ で行う以外は実施例1の方法で行った。得られた焼結体は半透明であった。 ( Comparative Example 1) The method of Example 1 was performed except that sintering was performed at 1550 ° C. The obtained sintered body was translucent.
Claims (2)
1 3 0 0 calcined primary particle diameter of 1 0 nm to 3 0 0 nm preparation of scandium oxide Sinterable powder in the temperature range ° C. from 1 0 0 0 ° C. The sulfuric acid Sukanjiu beam.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004026606A JP4051449B2 (en) | 2004-02-03 | 2004-02-03 | Method for producing transparent scandium oxide sintered body using sulfate as precursor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004026606A JP4051449B2 (en) | 2004-02-03 | 2004-02-03 | Method for producing transparent scandium oxide sintered body using sulfate as precursor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2005219938A JP2005219938A (en) | 2005-08-18 |
| JP4051449B2 true JP4051449B2 (en) | 2008-02-27 |
Family
ID=34995870
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2004026606A Expired - Lifetime JP4051449B2 (en) | 2004-02-03 | 2004-02-03 | Method for producing transparent scandium oxide sintered body using sulfate as precursor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4051449B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102030355A (en) * | 2010-10-27 | 2011-04-27 | 攀枝花市硕盛工贸有限公司 | Process for extracting discandium trioxide by utilizing waste acid from titanium dioxide plants |
| US11142809B2 (en) | 2015-02-10 | 2021-10-12 | Scandium International Mining Corp. | Systems and processes for recovering scandium values from laterite ores |
| JP6128166B2 (en) * | 2015-06-22 | 2017-05-17 | 住友金属鉱山株式会社 | Method for producing scandium oxide |
-
2004
- 2004-02-03 JP JP2004026606A patent/JP4051449B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JP2005219938A (en) | 2005-08-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Saito et al. | Fabrication of transparent yttria ceramics at low temperature using carbonate‐derived powder | |
| Wen et al. | Synthesis of yttria nanopowders for transparent yttria ceramics | |
| Ganesh et al. | Effect of fuel type on morphology and reactivity of combustion synthesised MgAl2O4 powders | |
| WO2003004437A1 (en) | Translucent rare earth oxide sintered article and method for production thereof | |
| JPS63123813A (en) | Yttrium oxide ceramic product | |
| JP2939535B2 (en) | Manufacturing method of transparent yttrium oxide sintered body | |
| Zawrah et al. | Synthesis andcharacterisation of nanocrystalline MgAl2O4 ceramic powders by use of molten salts | |
| CN107001153B (en) | Method for producing sulfide-based ceramic elements, in particular for IR optical applications | |
| JP2003089578A (en) | Light transmittable rare earth oxide sintered compact, and production method therefor | |
| Li et al. | Fabrication of transparent Sc2O3 ceramics with powders thermally pyrolyzed from sulfate | |
| US5474959A (en) | Process for the production of K- or Rb-β"- or -β- aluminum oxide ion conductors | |
| US4769353A (en) | Strontium-containing yttrium oxide ceramic body | |
| Dobretsova et al. | The influence of the Sc 3+ dopant on the transmittance of (Y, Er) 3 Al 5 O 12 ceramics | |
| JP4051449B2 (en) | Method for producing transparent scandium oxide sintered body using sulfate as precursor | |
| de Souza et al. | Mullite Whiskers Grown from Erbia‐Doped Aluminum Hydroxide–Silica Gel | |
| JP4251649B2 (en) | Translucent lutetium oxide sintered body and method for producing the same | |
| JP2002154870A (en) | Method for producing transparent spinel sintered compact | |
| US11136271B2 (en) | Aluminum nitride particles | |
| JP3906352B2 (en) | Method for producing YAG transparent sintered body | |
| JP2010126430A (en) | Translucent yag polycrystal body and method of manufacturing the same | |
| RU2705848C1 (en) | Single-phase polycrystalline yttrium-aluminum garnet, activated with erbium, ytterbium, and a method for production thereof | |
| EP3560905B1 (en) | Transparent aln sintered body and production method therefor | |
| JPS63303863A (en) | Aluminum nitride sintered body having high thermal conductivity and its production | |
| JP2009184898A (en) | Translucent ceramics | |
| Li et al. | Preparation and infrared transmittance of NaLaS2 ceramics |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20070809 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20070821 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20070920 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20071106 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4051449 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| EXPY | Cancellation because of completion of term |