AC susceptibility and electrical properties of Ta substituted (Tl1−xTax)(BaSr)CaCu2O7 superconductor (x = 0–0.3). (January 2021)

• Record Type: Journal Article
• Authors: Jannah, A.N.; Ilhamsyah, A.B.P.; Abd-Shukor, R.
• Is Part Of: Cryogenics. Volume 113(2021)
• Publication Date: 2021-01
• Subjects: Ta2O5 -- Microstructure -- Ionic radius -- Current density; Low temperature engineering -- Periodicals; Low temperature research -- Periodicals; 536.56
• DOI: 10.1016/j.cryogenics.2020.103222
• Languages: English
• ISSNs: 0011-2275

Abstract

Highlights: Ta was substituted in (Tl1 −x Ta x )(BaSr)CaCu2 O7. Josephson coupling energy showed that the flux pinning increased for x = 0.3. The x = 0.3 samples showed an increase in T p indicating the enhancement of inter-grain coupling. Abstract: The effects of Ta substitutions on the superconducting properties of (Tl1 −x Ta x )(BaSr)CaCu2 O7 for x = 0, 0.1, 0.2 and 0.3 are reported. X-ray diffraction patterns showed a single Tl-1212 phase for the x = 0 samples. Unreacted Ta2 O5 peaks were observed in all Ta substituted samples. The electrical resistance versus temperature curves showed metallic normal state behavior. The transition temperature and maximum intergrain Josephson current decreased for x = 0. 1 and 0.2 but increased for x = 0.3 samples. The intergranular critical current density, J c at the peak temperature, T p of the imaginary part of the susceptibility was between 15 and 22 A cm −2 . The x = 0.3 samples showed an increase in T p indicating the enhancement of inter-grain coupling. The Josephson coupling energy, E J showed that the intergranular coupling and flux pinning energy decreased for x ≤ 0.2 but increased for x = 0.3 samples. The roles of Ta2 O5 in the Tl(BaSr)CaCu2 O7 superconductors are discussed.