Thermoelectric Power of High-pressure Synthesized CuBa2Ca3Cu4O−δ

[[abstract]]We report measurements of thermoelectric power (TEP) for high-pressure synthesized CuBa2Ca3Cu4O11-δ superconductors. The magnitude of TEP for the sample with Tc,zero=115.9 K is very small and shows a sign crossover at ∼160 K. The TEP shows a peak behavior and displays an approximately linear temperature dependence with a negative slope -0.033 μV/K2 for 120≤T≤240 K. These features resemble those for other known high-Tc cuprate superconductors, in particular Sa in the a direction for an untwinned YBa2Cu3O7-δ single crystal and polycrystalline Tl-2201 samples. A brief discussion is given on the TEP behavior in comparison with CuBa2YCu2O7-δ cuprate superconductors by considering their similar structure of building blocks and type of charge reservoir