ABSENCE OF OXYGEN STOICHIOMETRY EFFECTS ON TC IN A TL-1122 SUPERCONDUCTOR
Journal
Physica C
Journal Volume
161
Journal Issue
4
Pages
523-526
Date Issued
1989
Author(s)
Abstract
In all of the two-Bi-layer compounds Bim (Ca, Sr)n+1CunO2n+4+δ (m=2, n=1,2 or 3) and their Tl-analogues small changes in the oxygen stoichiometry δ may be obtained by annealing in different oxygen partial pressures and temperatures resulting in substantial changes in the superconducting Tc. Tc maximises as a function of δ and may fall 30 K or more either side of the maximum. We have now investigated an m=1 single Tl-layer 1122 compound Tl0.5Pb0.5Ca0.8Y0.2Sr2Cu2Oy and find no such annealing effects. Oxygen stoichiometry effects for m=2 and their absence for m=1 suggests oxygen loading in the former case occurs interstitially between the double Bi- or Tl-layer. © 1989.
Type
journal article