ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Bulk Y1Ba2Cu3O7−δ 5 superconductors were prepared from initial mixtures of a precursor and Csl or commercial 123 Hoechst powder and Csl with the nominal composition Y1Ba2Cu3Cs x O y (x = 0,0.05, 0.1,0.2 and 0.3). Different synthesis regimes were applied in order to determine the influence of normal or reduced oxygen pressure as well as vacuum when isothermal heating at 800 °C is performed during sintering. It was found that heating at 800 ° C with reduced oxygen pressure favourably affects the J c and density of the samples in the case where 123 powder is used as the starting material. When the precursor is used the intensive dissociation of BaCO3 at low pressure leads to higher porosity and deterioration of the superconducting properties. Adding Cs in small concentrations promotes higher J c and density of specimens made from the precursor, but when commercial 123 powder is used, a negative effect is observed due to the chemical instability of the superconducting phase. Atomic absorption spectrometry reveals that the Cs disappears during sintering and, therefore, could be used in small concentrations as a fluxing additive without any risk of creating Cs-containing impurity phases.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00356013
Permalink