Elemental Substitution at Tl Site of Tl[sub.1−x]XIx/ICaCu[sub.2]O[sub.7] Superconductor with X = Cr, Bi, Pb, Se, and Te

• Published in: Materials 2023-05, Vol.16 (11)
• Main Authors: Nur-Akasyah, Jaafar, Abd-Shukor, Roslan, Chong, Tet Vui
• Format: Article
• Language: English
• Subjects: Superconductors
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma16114022

The effects of elemental substitutions at the Tl site of a Tl[sub.1−x]Xx(Ba, Sr)CaCu[sub.2]O[sub.7] superconductor with X = Cr, Bi, Pb, Se, and Te were investigated. This study aimed to determine the elements that enhance and suppress the superconducting transition temperature of the Tl[sub.1−x]Xx(Ba, Sr)CaCu[sub.2]O[sub.7] (Tl-1212) phase. The selected elements belong to the groups of transition metal, post-transition metal, non-metal, and metalloid. The relationship between the transition temperature and ionic radius of the elements was also discussed. The samples were prepared by the solid-state reaction method. The XRD patterns showed a single Tl-1212 phase was formed in the non- and Cr-substituted (x = 0.15) samples. The Cr-substituted samples (x = 0.4) showed a plate-like structure with smaller voids. The highest superconducting transition temperatures (T[sub.c onset], T[sub.cχ′], and T[sub.p]) were also achieved by the Cr-substituted samples for x = 0.4 compositions. However, the substitution of Te suppressed the superconductivity of the Tl-1212 phase. J[sub.c inter] (T[sub.p]) for all samples was calculated to be in the range of 12-17 A/cm[sup.2]. This work shows that substitution elements with a smaller ionic radius tend to be more favorable in improving the superconducting properties of the Tl-1212 phase.