Resistivity and thermoelectric power of [formula omitted] superlattice with 2-unit-cell-thick YBa 2Cu 3O 7−δ layer in one period

Abstract

Measurements of the resistivity and thermoelectric power (TEP) for a series of YBa 2Cu 3O 7−δ PrBa 2Cu 3O 7−δ ( YBCO PrBCO ) superlattice samples with 2-unit-cell-thick YBCO layer and 2, 4, 6 or 8-unit-cell-thick PrBCO layer in one period are reported. For the sample with 2-unit-cell-thick PrBCO layers, the resistivity of the YBCO layers is larger than that of bulk YBCO samples. The contribution of stoichiometric diffusion and interface scattering is estimated. Its TEP is positive with positive temperature coefficient, different from the typical negative one in bulk YBCO samples with positive TEP values. The property of the YBCO layers changes with increasing thickness of the PrBCO layers. For the sample with 8-unit-cell-thick PrBCO layers, the contribution of the PrBCO layers has to be considered.