| Budget Amount *help |
¥9,200,000 (Direct Cost: ¥9,200,000)
Fiscal Year 1999: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1998: ¥7,200,000 (Direct Cost: ¥7,200,000)
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| Research Abstract |
The aims of this project are 1) to make clear whether the so-called, long range proximity effect found in junctions using perovskite Mn oxides as a barrier, is real or not., 2) to fabricate high performance Josephson junctions using these barriers, and 3) to investigate physical properties of perovskite Mn oxides.
To 1), fabrication of thin films with a very small number of droplets inherent in the PLD method is crucial. We tried fabrication using the so-called eclipse method and attained drastic decrease of droplets. In this research, we could not apply this method in fabricating junctions, but plan to do this in future to realize the aims 1) and 2). As to 3), we fabricated thin films of Nd(0.5)Ba(0.5)MnO(3-x), Y(0.5)Ba(0.5)MnO(3-x), and La(1-z)Ba(y)Ca(z-y)MnO(3-x). We fabricated good films with rather flat surface. In future, we use these materials as a barrier. We found a quite anomalous behavior in La(1-z)Ba(y)Ca(z-y)MnO(3-x) thin films. With addition of Ba to La(1-z)Ca(z)MnO(3-x), the film showed insulator to metal transition at low temperature, but, its magneto resistance turned out quite anomalous. It showed a positive magnetoresistance which is quite unusual in perovskite Mn oxides.
In Pr(0.5)Ca(0.5)MnO(3-x) thin films, we observed strong decrease of the electrical resistance under application of external electric field as was found in single crystals.
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