| Project/Area Number |
61850045
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
電力工学
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| Research Institution | Tohoku University |
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Principal Investigator |
ANAYAMA Takeshi Faculty of Eng., Tohoku University, Prof., 工学部, 教授 (20005177)
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| Co-Investigator(Kenkyū-buntansha) |
SATO Michio Faculty of Eng., Tohoku Niversity, Research Associate, 工学部, 助手 (30110654)
SUZUKI Mitsumasa Faculty of Eng., Tohoku Niversity, Assoiate Prof., 工学部, 助教授 (40091706)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1987: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1986: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | Superconducting Magnet / A15 compound / Nb_3Ge / Thin film / 超電導マグネット |
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| Research Abstract |
In order to produce superconducting Nb3Ge tapes and to evaluate their high field properties, A15 Nb_3Ge has been continuously formed on a Hastelloy-B tape by Chemical Vapor Deposision(CVD). Nbcl_5 powder and liquid gecl_4 were used as starting materials. Nbcl_5 vapor wad generated by heating the NbCl_5 powder and was carrid to a mixer by gaseous Ar. GeCl_4 vapor was produced by passing Ar through the liquid GeCl_4 and was introduced to the mixer. These chlotides were mixed with H_2 gas and were sprayed on a moving tape of Hastelloy-B in the reaction chamber hild at a temperature of 800-900゜C. Experimental results ara summarized as fllows.
1. Reaction temperatures higher than 850゜C are required for growth of A15 Nb_3Ge on a Hastgelloy-B substrate.
2. Superconducting Nb_3 Ge tapes with high Tc and high Jc contain a small amount of Nb_5Ge_3 phase.
3. There is an appreciable reaction between deposited Nb_3Ge layer and Hastelloy-B substrate in the case of deposition tuns at a low speed. Namely, when the temperature in the reaction chamber is less uniform over the deposition zone, deposited layer of A15 Nb_3Ge would be destroyed by moving in a higher temperature zone.
4. Under the optimum deposition conditions, -14cm long Bn3Ge tapes with good uniformity of Tc have been prepared. The maximum Tc is 20.2K. The Jc at 15T is 7.7X10^4A/cm^2 and the Hc2 is -25.4T.
The present CVD apparatus provides a deposition rate of 0.3m/hr,but this rate is too small to produce Nb_3Ge tapes industrially. In future, the process of chlorinating directly Nb and Ge chips for formation of chlorides should be investigated.
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