Superconductivity and oxygen ordering in (Ca,Ba,La)Cu3O7−δ

T. Bjrnholm; I. K. Schuller; E. A. Early; M. B. Maple; B. Wuyts; J. Vanacken; Y. Bruynseraede

doi:10.1103/PhysRevB.41.11154

← Back to search

Superconductivity and oxygen ordering in (Ca,Ba,La)Cu3O7−δ

T. Bjrnholm, I. K. Schuller, E. A. Early, M. B. Maple, B. Wuyts, J. Vanacken, Y. Bruynseraede

DOI 10.1103/PhysRevB.41.11154 · Physical Review B

T1

Active bibliographic source — not scientific approval

Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.

Abstract

Magnetization measurements on polycrystalline samples with nominal composition Y1−xCaxBa2−xLaxCu3O7−δ (x=0.0, 0.05, 0.10, 0.50, and 1.0) show that only samples with x=1.0 or 0.0 contain a single superconducting phase. Gas evolution experiments on (Ca,Ba,La)Cu3O7−δ (x=1.0, δ∼0.07) reveal the presence of an oxygen phase that is indistinguishable from the oxygen chain structure of YBa2Cu3O7−δ (x=0.0, δ∼0.05); however, the total amount of evolved oxygen is very different between the two phases. These studies suggest that two phases coexist in (Ca,Ba,La)Cu3O7−δ: a superconducting phase in which La3+ ions occupy the Y3+ sites, and a second nonsuperconducting phase where Ca2+ ions occupy the Y3+ sites.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
(Ca,Ba,La)Cu3O6.93 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	80.6	Pressure not reported	midpoint
(Ca,Ba,La)Cu3O6.93 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	80	Pressure not reported	onset
YBa2Cu3O7-δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	90	Pressure not reported	unknown