Superconductivity of TlSr1212 Derivatives with Mo and In Substitutions at Sr-Site

• Published in: Solid State Science and Technology (AIP Conference Proceedings Volume 909) Vol. 909; pp. 186 - 192
• Main Authors: Musa, B, Yahya, A K, Jumali, M H
• Format: Journal Article
• Language: English
• Published: 01.01.2007
• ISBN: 9780735404175; 0735404178
• ISSN: 0094-243X
• DOI: 10.1063/1.2739850

Derivatives of TlSr1212 type phase with nominal starting compositions of Tl0.9Bi0.1Sr2-xMoxCa0.9Y0.1Cu2O7(x = 0.0 - 0.4) and Tl0.9Bi0.1Sr2-yInyCaCu2O7(y = 0.0 - 0.5) were prepared and investigated by d.c. electrical resistance measurements, powder X-ray diffraction (XRD) and scanning electron microscope (SEM). Partial substitution of Mo for Sr initially increased Tczero and 1212 phase formation at x = 0.1 but both gradually deteriorated with increasing Mo. Partial substitution of In for Sr suppressed Tczero but maintained 1212 volume fraction between 69-73 %. Our results showed strong influence of the substitutions on the temperature dependence of the normal state resistance as well as Tc values and indicate that the substitutions successfully modified the number of charge carriers in the superconducting planes. Effects of the elemental substitutions on superconductivity of TlSr1212 are discussed in terms of ionic radius of dopants and the concept of average Cu valence.