Japanese Journal of Applied Physics · 1987 · 34 citations · 5 references
Natural SciencesMaterials SciencePhysicsCondensed Matter PhysicsCrystal StructureSolid State PhysicsCrystal ChemistryCrystal SystemsCrystallographyMagnetism In SolidsSuperconducting MaterialsX-ray CrystallographyCuprate SuperconductorsHigh-temperature SuperconductivityHigh-temperature SuperconductorsPhase Transition TemperatureSuperconducting PropertiesUnit Cell DeterminationUnit Cell ParametersX-ray Diffraction Analysis
High temperature superconductors La 2- x M x CuO 4- y (M=Ba and Sr) with the K 2 NiF 4 structure were synthesized by solid state reaction and characterized by X-ray diffraction, electron microscopy, IR measurements and thermogravimetry. Anomalous behavior of unit cell parameters was confirmed. Electron diffraction study of the orthorhombic La 2 CuO 4 revealed weak forbidden spots for Fmmm symmetry, suggesting a space group of lower symmetry. One of three IR bands observed in La 2 CuO 4 rapidly disappeared around x =0.1. Highest superconducting transition temperature was found to be 38.0 K in La 1.85 Sr 0.15 CuO 3.96 .
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High temperature superconductivity in the LiTiO ternary system
D. C. Johnston, Hari Prakash, W. H. Zachariasen et al. · Materials Research Bulletin · 1973 · 401 citations