Thermoelectric power in Bi2Sr2−xKxCaCu2Oy

TLDR: In this paper, the superconducting and normal state transport properties of ceramic samples with composition Bi 2 Sr 2−x K x CaCu 2 O y ( x ǫ = 0, 0.1, 0., 0.2, 0, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) have been investigated by measuring thermoelectric power.

Abstract: The superconducting and normal state transport properties of ceramic samples with composition Bi 2 Sr 2− x K x CaCu 2 O y ( x  = 0, 0.1, 0.2, 0.3, 0.4) have been investigated by measuring thermoelectric power. The samples were prepared by the solid state route, and single phase Bi-2212 was found for all compositions. The T c (0) and thermoelectric power data were collected from 50 to 300 K. The thermoelectric power changes slightly with increasing doping level and increases linearly with decreasing temperature reaching a maximum value at T c (0). The T c (0), hole concentration and thermoelectric data were correlated. The results obtained are analysed in terms of phenomenological theoretical models that makes it possible to determine the band spectrum parameters in the normal state and to trace their changes with varying composition. Following models applied such as (a) Hubbard model, (b) two-band model, (c) Fermi-liquid behaviour. Applicability of these models to the present HTSC system is discussed and the parameters related to the models have been evaluated.