Browsing by Author "Kovachev V."

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    Phase formation and microstructure in Re1-xCax Ba2Cu3Oz (Re=Y, Eu, Er; x=0, 0.2, 0.3) superconducting ceramics
    (2006-03-01) Stoyanova-Ivanova A.; Terzieva S.; Staneva A.; Mikli V.; Traksmaa R.; Dimitriev Y.; Kovachev V.
    We have investigated the influence of Ca-substitution and different rare earths on the microstructure of RE1-xCax Ba2Cu3O7-δ (RE= Y, Eu, Er; x=0, 0.2, 0.3) superconducting ceramics. Scanning electron microscopy, X-ray microanalysis and energy dispersive spectroscopy have been used to study the microstructure and the chemical composition of the samples. A correlation was established between the polycrystalline microstructure and phase formation depending on the additive content. We observed that calcium is distributed uniformly in the crystals. The formation of minor impurity phases improved the sintering conditions. © Central European Science Journals Warsaw and Springer-Verlag Berlin Heidelberg 2006.
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    Phase formation and microstructure in Re1-xCax Ba2Cu3Oz (Re=Y, Eu, Er; x=0, 0.2, 0.3) superconducting ceramics
    (2006-03-01) Stoyanova-Ivanova A.; Terzieva S.; Staneva A.; Mikli V.; Traksmaa R.; Dimitriev Y.; Kovachev V.
    We have investigated the influence of Ca-substitution and different rare earths on the microstructure of RE1-xCax Ba2Cu3O7-δ (RE= Y, Eu, Er; x=0, 0.2, 0.3) superconducting ceramics. Scanning electron microscopy, X-ray microanalysis and energy dispersive spectroscopy have been used to study the microstructure and the chemical composition of the samples. A correlation was established between the polycrystalline microstructure and phase formation depending on the additive content. We observed that calcium is distributed uniformly in the crystals. The formation of minor impurity phases improved the sintering conditions. © Central European Science Journals Warsaw and Springer-Verlag Berlin Heidelberg 2006.