ISSN:
1572-9540
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The local structure, magnetism, and superconductivity of Y1−z Ca z Sr2Cu3−y Fe y O6+x have been investigated by magnetic susceptibility,57Fe Mössbauer absorption spectroscopy, X-ray powder diffraction, and iodometric titration. By modification of the hole distribution between the Cu(1)O x chains and Cu(2)O2 sheets, we induced bulk superconductivity with a maximum superconducting critical temperatureT c near 20 K in Y−zCa z Sr2Cu2.5Fe0.5O6+x (0.05≤z≤0.18). We interpret the development of a broad maximum inT c and the Meissner fractionV f versusz nearz=0.12 to be due to an increasing transfer of holes from the Cu(1)O x chains to the Cu(2)O2 sheets induced by a shorterc-axis and reduced Coloumb repulsion of the positively charged Y1−z Ca z plane. The increase in hole transfer from the Cu(1)O x chains to the Cu(2)O2 sheets also modulates the magnetic ordering temperatureT m. We show thatT m of YSr2Cu2FeO7.26 is approximately 65 K, which is much lower than that observed in YBa2Cu2.31Fe0.69O7.21 (T m≈400 K).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02072925
