Ching-Lin Chang1 and Haw-Yee Tsay1

1Department of Physics Tamkang University, Tamsui, Taiwan 25137, R.O.C.


Received: December 1, 1997
Accepted: June 18, 1998
Publication Date: June 18, 1998

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It is well known that the hole concentration is a crucial parameter for superconductivity of the high temperature superconductors. When Ca+2 replaces part of R+3 in fully oxygenated RBa2Cu3O7-δ. The hole concentration increases with Ca+2 concentration bring the system into the overdoping regime and causing the superconducting transition temperature Tc to drop. The sites of the extra hole and that of the Ca are the key factors to the understanding of the electrical transport property of this Ca doped system. We have performed the EXAFS on R1-xCaxBa2Cu3O7-δ ( R=Gd, Ho ) at room temperature to study effect of Ca doping on the local structure.

Keywords: EXAFS, R1-xCaxBa2Cu3O7-δ , High Temperature Superconductors.


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