Nh. Hur et al., SUPERCONDUCTIVITY IN THE INDIUM-DOPED TL-1223 PHASE - (TL0.8IN0.2)(SR0.8BA0.2)(2)CA2CU3O9-DELTA, Physica. C, Superconductivity, 268(3-4), 1996, pp. 266-270
We report the synthesis and characterization of a new Tl- and In-based
'1223' type cuprate oxide, (Tl0.8In0.2)(Sr0.8Ba0.2)(2)Ca2Cu3O9-delta
(Tl,In-1223). The as-synthesized Tl,In-1223 compound becomes supercond
ucting at about 80 K, The T-c increased to 103 K when the sample was a
nnealed under an argon atmosphere, Magnetization studies on polycrysta
lline samples of Tl,In-1223 reveal that persistent current densities (
J(p)) of the indium-doped compound are about 10 times smaller than tho
se of corresponding TI,Bi-1223 and Tl,Pb-1223 with the same structure
type, Small substitution of In for Tl in Tl-1223 results in a large re
duction of T-c and J(p), A slight change in the electronic configurati
ons of the rock-salt metal sites appears to affect the delicate balanc
e of the metal and oxygen energy levels, which leads to the virtual ch
anges in the superconductivity in Tl,In-1223.