Jpn. J. Appl. Phys. 26 (1987) pp. L460-L462 |Next Article| |Table of Contents|
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Electronic Structures and Superconducting Mechanism of Ba2Y1Cu3O7
(Received March 16, 1987; accepted for publication March 23, 1987)
The high-Tc superconductor Ba2Y1Cu3O7 with the oxygen-deficient perovskite structure was prepared almost in a single-phase with Tco of 125 K, Tc of 95 and Tce of 93 K. The XPS valence-band spectrum showed a relative large N(EF), density of states at the Fermi level. The XPS Cu 2p3/2 peak is divided into three peaks which are attributed to monovalent, bivalent and trivalent Cu ions with the concentration ratio of 1:2:1. These results and the peculiar lattice structure lead to the Tc enhancement mechanism from the plasmon or exciton origin due to the Cu d-hole creation and annihilation resonating with vibration modes of the CuO5 and CuO4 clusters. The Tc value was calculated.
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