We successfully prepared a single-phase sample of TlSr2Ca2Cu3Oy by high pressure synthesis. The powder mixture with a nominal composition of TlSr2Ca2Cu3O9.4 was heat-treated at 1100 °C for 4 h under 6 GPa. Powder X-ray diffraction revealed that the obtained sample was single-phase of the 1223 structure with a tetragonal unit cell (a = 3.813(4) angstroms, c = 15.24(1) angstroms. The sample exhibited Meissner signals below 86 K. The resistivity linearly decreased with decreasing temperature above 86 K and the thermoelectric power at 290 K was found to be nearly zero. These results imply that the hole concentration of the sample is nearly optimized. The sample showed an excellent dependence of the irreversibility field Birr on reduced temperature (1-T/Tc), which is comparable to that for (Cu,C)-1223.
ASJC Scopus subject areas
- Condensed Matter Physics