A new superconductor obtained by electrochemical oxidation of La2CuO4

Abstract The electrochemical oxidation of La 2 CuO 4 in alkaline solution (1N KOH) has been used for preparing the superconducting phase La 2 CuO 4+δ (δ⋍0.07). Crystallographic data show an enhanced orthorhombic distortion and an increase of the unit cell volume. The transport properties reveal a sharp transition from a metallic behaviour to a superconducting state below 44 K which is corroborated by the noteworthy magnetic properties.

[1]  J. F. Kwak,et al.  Stoichiometry of bulk superconducting La2CuO4+δ: A superconducting superoxide? , 1988 .

[2]  G. Broers,et al.  Properties of La1−xSrxBO3−y (B=Co or Fe) compounds as oxygen electrodes in alkaline solution , 1978 .

[3]  P. Hagenmuller,et al.  Electrolytic oxygen evolution in alkaline medium on La/sub 1-x/Sr/sub x/FeO/sub 3-y/ perovskite-related ferrites. I. Electrochemical study , 1987 .

[4]  P. M. Raccah,et al.  The structure of La2CuO4 and LaSrVO4 , 1973 .

[5]  P. Hagenmuller,et al.  Electrolytic Oxygen Evolution in Alkaline Medium on La1 − x Sr x FeO3 − y Perovskite‐Related Ferrites II . Influence of Bulk Properties , 1987 .

[6]  Richards,et al.  Structure of the interstitial oxygen defect in La2NiO4+ delta. , 1989, Physical review. B, Condensed matter.

[7]  Venturini,et al.  Superconducting phase of La2CuO4-y: Superconducting composition resulting from phase separation. , 1988, Physical review. B, Condensed matter.

[8]  J. Bockris,et al.  The Electrocatalysis of Oxygen Evolution on Perovskites , 1984 .

[9]  Fisk,et al.  Electronic anisotropy in single-crystal La2CuO , 1988, Physical review. B, Condensed matter.

[10]  J. Tarascon,et al.  Superconductivity at 40 K in the Oxygen-Defect Perovskites La2-xSrxCuO4-y , 1987, Science.

[11]  S. Trasatti.  Electrodes of Conductive Metallic Oxides , 1981 .

[12]  J. Balej.  Electrocatalysts for oxygen evolution in advanced water electrolysis , 1985 .

[13]  A. Jacobson,et al.  Superconductivity and magnetism in the high TC copper oxides , 1988 .

[14]  Venturini,et al.  Identification of a superoxide in superconducting La2CuO4+ delta by x-ray photoelectron spectroscopy. , 1988, Physical review. B, Condensed matter.

[15]  A. Wattiaux,et al.  Phase conversion in La2CuO4 superconductors , 1990 .

[16]  McCarron,et al.  Question of superoxide in La2CuO4+ delta. , 1990, Physical Review B (Condensed Matter).

[17]  A. F. Wells,et al.  Structural Inorganic Chemistry , 1971, Nature.

[18]  K. Müller,et al.  Possible highTc superconductivity in the Ba−La−Cu−O system , 1986 .

[19]  H. Müller-Buschbaum,et al.  Über Oxocuprate. XV Zur Kristallstruktur von Seltenerdmetalloxocupraten: La2CuO4, Gd2CuO4 , 1977 .

[20]  Lewandowski,et al.  Influence of oxygen defects on the physical properties of La2CuO , 1987, Physical review. B, Condensed matter.

[21]  K. Amine,et al.  Stabilization of a new superconducting phase by low temperature fluorination of La2CuO4 , 1990 .