Oxidation state of copper in optimally oxygen-doped 1:2:3 Ca-La-Ba-Cu-O superconductors

A. Knizhnik; C. G. Kuper; Y. Eckstein

doi:10.1103/PhysRevB.58.11204

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Oxidation state of copper in optimally oxygen-doped 1:2:3 Ca-La-Ba-Cu-O superconductors

A. Knizhnik, C. G. Kuper, Y. Eckstein

DOI 10.1103/PhysRevB.58.11204 · Physical Review B

T1

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Abstract

This paper describes an investigation of the family “CLBLCO” of 1-2-3 superconductors CLBLCO [(CaxLa1−x)(Bac−xLa2−c+x)(Cu1−zMz)3Oy], with values x=0.1, 0.2, 0.3, and 0.4, c=2.00, 1.75, and 1.55. The impurity M substituting for Cu was one of Zn, Ni, Co, and Ga, and the value of z was taken from zero to 0.1. Although the maximal value of the transition temperature Tc occurs at different values of the oxygen content y, the average oxidation state of copper for maximal Tc is found to be approximately constant. The data for Ni-doped CLBLCO suggest that the oxidation state of Ni in this system appears to be 3.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
(CaxLa1-x)(Bac-xLa2-c+x)(Cu1-zMz)3Oy Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown
(CaxLa1-x)(Ba1.75-xLa0.25+x)Cu3Oy Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	onset
(CaxLa1-x)Ba1.75-xLa0.25+x(Cu1-zMz)3Oy Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	onset