ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The oxide superconductor YBa2Cu3O7−δ is known to have a rather free entrance of oxygen into the CuO chain between the BaO layers, and the oxygen deficiency δ is closely related with the critical temperature Tc. (1) When Y3+ site is substituted with Ca2+, the position of the oxygen vacancy is not on the Cu–O plane, but on the CuO chain as well as in the case of YBa2Cu3O7−δ. (2) When this substitution is done, electric neutrality is kept by the release of a half O2− for one Y3+ substitution with one Ca2+. (3) Therefore, the concentration of the positive hole is constant for this substitution, and Tc of the system is kept at the rather high temperature of about 86 K. (4) The relation between Tc and the hole concentration is in good agreement with the non-Ca2+ containing YBCO, and it can be said as a conclusion that the substitution of Y3+ with Ca2+ does not give any effect on the mechanism of the superconductivity of this system. (5) The crystallinity of the system is improved by the substitution to be better sintered and to have more narrow width of the critical temperature.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.348014
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