Superconducting, structural and thermochemical properties of La2CuO4+δ prepared by KMnO4 oxidation

E. Takayama-Muromachi; A. Navrotsky

doi:10.1016/0921-4534(93)90279-Y

Superconducting, structural and thermochemical properties of La₂CuO_4+δ prepared by KMnO₄ oxidation

E. Takayama-Muromachi, A. Navrotsky

Research output: Contribution to journal › Article › peer-review

39 Scopus citations

Abstract

La₂CuO_4+δ having various δ values was prepared by the KMnO₄ oxidation method in aqueous solutions at 333 K. Some samples oxidized in concentrated KMnO₄ solutions underwent spinodal decomposition resulting in products having δ∼0.01 and δ∼0.22. The former showed a superconducting transition at ∼ 14 K, the latter at 40 K. The partial molar enthalpy of excess oxygen up to ∼ -57 kJ/mol O was obtained for La₂CuO_4+δ by high-temperature drop calorimetry. This value suggests that La₂CuO_4+δ is, disregarding the spinodal decomposition, thermodynamically stable in oxygen fugacities less than 1 atm at room temperature.

Original language	English (US)
Pages (from-to)	164-174
Number of pages	11
Journal	Physica C: Superconductivity and its applications
Volume	218
Issue number	1-2
DOIs	https://doi.org/10.1016/0921-4534(93)90279-Y
State	Published - Dec 1 1993
Externally published	Yes

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Condensed Matter Physics
Energy Engineering and Power Technology
Electrical and Electronic Engineering

Access to Document

10.1016/0921-4534(93)90279-Y

Cite this

@article{eca1ed8bc70844cea43212a3b2a75990,

title = "Superconducting, structural and thermochemical properties of La2CuO4+δ prepared by KMnO4 oxidation",

abstract = "La2CuO4+δ having various δ values was prepared by the KMnO4 oxidation method in aqueous solutions at 333 K. Some samples oxidized in concentrated KMnO4 solutions underwent spinodal decomposition resulting in products having δ∼0.01 and δ∼0.22. The former showed a superconducting transition at ∼ 14 K, the latter at 40 K. The partial molar enthalpy of excess oxygen up to ∼ -57 kJ/mol O was obtained for La2CuO4+δ by high-temperature drop calorimetry. This value suggests that La2CuO4+δ is, disregarding the spinodal decomposition, thermodynamically stable in oxygen fugacities less than 1 atm at room temperature.",

author = "E. Takayama-Muromachi and A. Navrotsky",

year = "1993",

month = dec,

day = "1",

doi = "10.1016/0921-4534(93)90279-Y",

language = "English (US)",

volume = "218",

pages = "164--174",

journal = "Physica C: Superconductivity and its applications",

issn = "0921-4534",

publisher = "Elsevier",

number = "1-2",

}

TY - JOUR

T1 - Superconducting, structural and thermochemical properties of La2CuO4+δ prepared by KMnO4 oxidation

AU - Takayama-Muromachi, E.

AU - Navrotsky, A.

PY - 1993/12/1

Y1 - 1993/12/1

N2 - La2CuO4+δ having various δ values was prepared by the KMnO4 oxidation method in aqueous solutions at 333 K. Some samples oxidized in concentrated KMnO4 solutions underwent spinodal decomposition resulting in products having δ∼0.01 and δ∼0.22. The former showed a superconducting transition at ∼ 14 K, the latter at 40 K. The partial molar enthalpy of excess oxygen up to ∼ -57 kJ/mol O was obtained for La2CuO4+δ by high-temperature drop calorimetry. This value suggests that La2CuO4+δ is, disregarding the spinodal decomposition, thermodynamically stable in oxygen fugacities less than 1 atm at room temperature.

AB - La2CuO4+δ having various δ values was prepared by the KMnO4 oxidation method in aqueous solutions at 333 K. Some samples oxidized in concentrated KMnO4 solutions underwent spinodal decomposition resulting in products having δ∼0.01 and δ∼0.22. The former showed a superconducting transition at ∼ 14 K, the latter at 40 K. The partial molar enthalpy of excess oxygen up to ∼ -57 kJ/mol O was obtained for La2CuO4+δ by high-temperature drop calorimetry. This value suggests that La2CuO4+δ is, disregarding the spinodal decomposition, thermodynamically stable in oxygen fugacities less than 1 atm at room temperature.

UR - http://www.scopus.com/inward/record.url?scp=0027849069&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027849069&partnerID=8YFLogxK

U2 - 10.1016/0921-4534(93)90279-Y

DO - 10.1016/0921-4534(93)90279-Y

M3 - Article

AN - SCOPUS:0027849069

SN - 0921-4534

VL - 218

SP - 164

EP - 174

JO - Physica C: Superconductivity and its applications

JF - Physica C: Superconductivity and its applications

IS - 1-2

ER -

Superconducting, structural and thermochemical properties of La₂CuO_4+δ prepared by KMnO₄ oxidation

Abstract

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this