|| Checking for direct PDF access through Ovid
The temperature dependence of the thermoelectric power of calcium substituted YBa2−xCaxCu3O7−δ pellets with 0≤x ≥ 1.5 is presented between 60 K and 300 K. A metal–insulator transition was reported earlier by us in this system and was attributed to the ionic size-dependent localization effect. While the sign of thermoelectric power of all the calcium substituted samples was found to be positive, its magnitude increases significantly with calcium content in YBCO. The normal state thermoelectric power data of substituted YBa2−xCaxCu3O7−δ (0≤x ≥ 1.5) are discussed in light of a two-band model originally proposed by Gottwick et al. for heavy fermion systems and later modified by Forro et al.