Influence of Se and Te substitutions at Tl-site of Tl(Ba, Sr)CaCu2O7 superconductor on the AC susceptibility and electrical properties. Issue 22 (15th November 2021)

• Record Type: Journal Article
• Authors: Nur-Akasyah, J.; Ranjbar, M.G.; Abd-Shukor, R.
• Is Part Of: Ceramics international. Volume 47:Issue 22(2021)
• Page Start: 31920
• Page End: 31926
• Publication Date: 2021-11-15
• Subjects: AC susceptibility -- Electrical resistance -- Ionic radius -- X-ray diffraction; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2021.08.078
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: The Sr and Ba bearing Tl-1212 phase, Tl(Ba, Sr)CaCu2 O7 is an interesting superconductor. The Sr only bearing TlSr2 CaCu2 O7 is not easily prepared in the superconducting form. The Ba only bearing TlBa2 CaCu2 O7 on the other hand does not show improvement in the transition temperature with elemental substitution. In this work the influence of multivalent Se (non-metal) and Te (metalloid) substitutions at the Tl-site of Tl1- x M x (Ba, Sr)CaCu2 O7 (M = Se or Te) superconductors for x = 0–0.6 was studied. The samples were prepared via the conventional solid-state reaction method. XRD patterns showed a single Tl-1212 phase for x = 0 and 0.1 Se substituted samples. The critical current density at the peak temperature, T p of the imaginary (χ") part of the AC susceptibility (χ = χ' +χ"), J c-inter ( T p ) for all samples was between 15 and 21 A cm −2 . The highest superconducting transition temperature was shown by the x = 0.3 Se-substituted sample ( T c-onset = 104 K, T c-zero = 89 K, T cχ' = 104 K and T p = 80 K). Te suppressed the superconductivity of Tl-1212 phase. The order of highest transition temperatures are as follows: Tl1- x Te x (Ba, Sr)CaCu2 O7 <Tl(Ba, Sr)CaCu2 O7 1- x Se x (Ba, Sr)CaCu2 O7 . This work showed that Se was better than Te in improving the transition temperature and flux pinning of the Tl-1212 phase. The roles of ionic radius of Se and Te on the superconductivity of Tl(Ba, Sr)CaCu2 O7 are discussed in this paper.