Cu1−xTlxBa2Ca3Cu4O12−y (Cu1−xTlx-1234) superconductor with Tc=126 K

The samples of Cu 1−x Tl x Ba 2 Ca 3 Cu 4 O 12−y (x=0∼0.5) system with low Tl concentration were prepared by a high pressure techniques. The Cu 1−x Tl x Ba 2 Ca 3 Cu 4 O 12−y (Cu 1−x Tl x -1234: x=0.4∼0.5) samples show Tc of 126 K and superconducting anisotropy of γ=4. Their Tc values are higher than those of parent materials of CuBa 2 Ca 3 Cu 4 O 12−y (Cu-1234) and TlBa 2 Ca 3 Cu 4 O 11 (Tl-1234) by 8 K and 4 K, respectively. The anisotropy of Cu 1−x Tl x -1234 system is close to the value (γ=3.5) of Tl-1234 and higher than that of Cu-1234 (γ=1.6.