Growth and Development of Large ZnO Single Crystals of High Purity by Hdrothermal Method under A Partial Pressure of Oxygen
| Project/Area Number |
02555061
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
電子材料工学
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| Research Institution | AKITA NATIONAL COLLEGE OF TECHNOLOGY |
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Principal Investigator |
SAKAGAMI Noboru AKITA NATIONAL COLLEGE OF TECHNOLOGY・Electrical Engineering・Professor, 電気工学科, 教授 (10006257)
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| Co-Investigator(Kenkyū-buntansha) |
SATO Masahiro AKITA NATIONAL COLLEGE OF TECHNOLOGY・Electrical Engineering・Research Associate, 電気工学科, 助手 (90132563)
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| Project Period (FY) |
1990 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 1992: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1991: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1990: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | ZnO single crystal / hydrothermal method / high purity / coulometry / stoichiometry / excess Zn atoms / oxygen pressure / O atomic vacancy / 高純度ZnO単結晶 / ZnOのストキオメトリ- / 酸素分圧制御水熱法 / ZnOのストイキオメトリ- |
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| Research Abstract |
Zinc oxide single crystals of high purity have been grown by the hydrothermal method under a partial pressure of oxigen,using a platinum-lined autoclave and ultra-pure reagents. The stoichiometry of the grow n crystals was investigatedby employing coulometric technique to detect a small deviation in the stoichiometric constituent towards Zn_<1+x>O. Large ZnO single crystals of high purity could be obtained at a growth rate of about 0.2 mm/d ay in a direction normal to a prismatic face (1010). The single crystals of ZnO up to 20X6X6mm^3 in size have been grown by this hydrothermal method.
The concentration of the excess Zn atoms,X_<zn> was accurately determined from 0.8 to 1.7 ppm and the electrical resistivity, rho of the as-grown crystals was the order of 10^8 OMEGA cm. The stoichiometry of th e grown crystals was investigated, and compared with the results (X_<zn> and rho are about 20 ppm and 10 OMEGA cm respectively) obtained for the crystal grown the condition without oxygen pressure. Comparing the crystals of the present work with them of the previous work ,it becomes evident that the decrease of the values of X _<zn> is chiefly caused by the effect of oxidation or the partial pressure of oxygen,and the resistivity drasticqlly increases. We consider that the L i^+ acts as an acceptor compensating the substitutional zinc because the O atomic vacancies are decreased under the oxidizer-added condition. Optical,dielectrical and piezoelectrical properties have been investigated,and compared wit h the crystals grown under the condition with no added oxygen.
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Report
(3 results)
Research Products
(14 results)
