| Co-Investigator(Kenkyū-buntansha) |
NOHIRA Toshiyuki Kyoto Univ., Energy.Science, Research Associate, エネルギー科学研究科, 助手 (00303876)
GOTO Takuya Kyoto Univ., Energy.Science, Research Associate, エネルギー科学研究科, 助手 (60296754)
HAGIWARA Rika Kyoto Univ., Energy Science, Assistant Professor, エネルギー科学研究科, 助教授 (30237911)
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| Budget Amount *help |
¥13,500,000 (Direct Cost: ¥13,500,000)
Fiscal Year 2003: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2002: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2001: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 2000: ¥10,100,000 (Direct Cost: ¥10,100,000)
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| Research Abstract |
We succeeded in constructing anew electrolysis cell in an argon glove box having a gas purification equipment. By using this apparatus, we conducted anodic electrolysis at various kinds of metal electrodes in a molten LiCI-KCl-Li:3N system at 723-773 K to nvestigate the electrochemical implantation of nitrogen. We succeeded in the formations of Ti-N, Fe-N, Al-N, Zr-N, Ga-N, Cr-N, Zn-N, SUS 430-N, SUS304-N. It was found that the addition of LiH to the melt is effective to accelerate the formation rate of the nitrides. It is a characteristic of this method to be able to control the nitrogen concentration in nitrides by electrolysis potential. In addition, the rate controlling process in the nitride growth was found to be the diffusion of nitrogen atoms in the nitride layer since the growth obeyed the parabolic rate law. We also investigated the electrochemical implantation of various rare earths (RE) into some transition metal substrates, which was conducted by eathodic polarization of the transition metal electrodes in molten LiCI-KCI-RECI3 systems, where RE = Y, La, Ce, Pr, Nd, Sin, Gd, Tb, Dy, Er and Yb. We found that some selected alloy phases, i.e., Ni_2Y, Ni_2La, Ni_2Ce, Ni_2Pr, Ni_2Nd, Ni_2Sm, Ni_2Dy, Ni_2Yb, CoGd:_3, Pd_3Y, Pd_3La, Pd_3Ce and Si_2Er, are formed quite rapidly. According to the transmission electron microscopy, the cause of the rapid formation was indicated to be due to the fast diffusion of atoms near the grain boundaries. When the.rapidly formed rare earth alloys were anodically polarized in the same melt, it was possible to dissolve only the rare earth elements from the electrodes, which was termed "electrochemical displantation". For the electrochemical, displantation, rare earth concentrations in the alloys can be controlled by electrolysis potential and quantity of electricity.
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