Enhanced Critical Current in Tl-Ba-Ca-Cu-O Superconductors Prepared by Diffusion Process with Fluorine Addition

Abstract

A brief qualitative mapping is given between austenite, tweed and twinned phases of martensite alloys and corresponding paramagnetic, spin glass and periodic phases in spin glass alloys. This paper is dedicated to John Pendry in celebration of his 65th birthday.

A Search for a Low Anisotropic Superconductor

“…The carbon can also form non-superconductor phases in the form of carbonates of Ba and/or Ca. [88] in the starting composition of Tl-1223 enhances the formation of single phase Tl-1223 material with out any Pb or Srdoping and increases J c (77K, 0T) and irreversibility field H irr [90,91]. The thin films of Tl-1223 prepared by using TlF are found to have critical current density of 4.410 6 A/cm 2 at 77K in zero field [84].…”

Effect of anion concentration in substitution for in the Bi-Pb-Sr-Ca-Cu-O (2223-phase) system superconductor

“…Moreover, it is a fact that the critical current density in the BSCCO system is remarkably improved with degree of densification of the sample [19,20]. The doping of an extremely small amount of fluorine ion into the superconductors of the Tl-and Hg-systems enhanced the critical current densities of the samples in a magnetic field [21,22]. It is already known that the BSCCO system superconductor expands noticeably its volume by sintering because of CaO contained in the system and weak-link connectivity essentially results.…”