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Impurity Substitution in Bismuth and Thallium Cuprates: Suppression of T_c and Estimation of Pseudogap

Biplab Chattopadhyay·B. Bandyopadhyay·Asok Poddar·P. Mandal·A. N. Das·B. Ghosh
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Abstract

Suppression of T_c in bilayer bismuth and thallium cuprates, by substitution of Co impurities at Cu sites, are taken for examination. T_c suppression data on differently doped Bi2212 and Tl2212 are analysed within the unitary pair-breaking formalism due to Abrikosov and Gorkov, by fitting data points to a phenomenological relation valid for weak coupling d-wave superconductors. Values of the pseudogap magnitude at each doping are thereby estimated within a "fermi-level density of states suppression" picture. Pseudogap magnitude from our estimation is observed to have a correspondence with a related characteristic temperature T^\star obtained by thermoelectric power measurements. Effects of pseudogap, on the density of states, is studied by calculating the susceptibility which shows a broad peak at high temperature. This peak feature in susceptibility is indicative of an unusual metallic state which could further be explored by systematic other measurements.

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Biplab Chattopadhyay, B. Bandyopadhyay, Asok Poddar, P. Mandal, A. N. Das, B. Ghosh. 1999-12-02. Impurity Substitution in Bismuth and Thallium Cuprates: Suppression of T_c and Estimation of Pseudogap. https://doi.org/10.1016/s0921-4534(99)00668-1

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