SUPERCONDUCTIVITY AND THERMOELECTRIC POWER IN Tl₂Ca₂Ba₂Cu₃O₁₀ AND TlCa₃BaCu₃O₉

Abstract

We report the synthesis and superconducting temperature of the high-T c compounds Tl 2 Ca 2 Ba 2 Cu 3 O 10 and TlCa 3 BaCu 3 O 9 . The transition to the superconducting state was measured by the magnetic susceptibility changes and by the temperature dependence of the electrical a.c. and d.c. resistivity and by thermoelectric power measurements. For Tl 2 Ca 2 Ba 2 Cu 3 O 10 a superconducting transition with zero resistance at 114.5K have been observed. Higher T c with zero resistance at 122K have been found in TlCa 3 BaCu 3 O 9 .