Springer Online Journal Archives 1860-2000
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Abstract An analysis of the composition of Ce and Tb barium copper oxide samples with the nominal composition CeBa2Cu3Oy and TbBa2Cu3Oy, prepared with the same solid state reaction method used for the other superconducting rare earth (R) barium copper oxide RBa2Cu3O7-δ compounds, is described. The analysis indicates that these samples are multiphase and consist mostly of 1) the perovskite phases BaCeO3 or BaTbO3, 2) CuO, and 3) BaCuO2. No trace of the oxygen deficient orthorhombic perovskite type structure of YBa2Cu3O7-δ could be found in the X-ray diffraction patterns. Consequently, the compounds do not display superconductivity. The magnetization measurements indicate that BaCeO3 is weakly paramagnetic which is consistent with tetravalent Ce. The BaTbO3 compound exhibits an antiferromagnetic transition at a Néel temperature TN-35 K, and its magnetic susceptibility above TN can be described by a Curie-Weiss law with an effective moment that corresponds to tetravalent Tb.
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