Superconductig compounds of pseudo-ternary (Y, La, Ba)3Cu3Oysystem were synthesized and crystallographic parameters and superconducting properties were measured. Compounds of YBa2_xLaxCu3Oyseries were found to be single phase up to x=l and orthorhombic to tetragonal transition at room temperature took place with x=0.5. Tc decreased with increasing x and superconductivity disappeared for x>0.6. These results can be interpreted to be due to the decrease In average valence of copper ions from 2.33 of YBa2Cu3O7with increasing x, which was caused by the substitution of divalent Ba Ions by trivalent La ions. On the other hand complete solid solution was formed for Yj_xLaxBa2Cu3Oyseries, where Tc decreased gradually with increasing x. Considerable increase In Tc was found for the La substituted specimens by annealing around 400°C for 24hrs.
|ジャーナル||Journal of the Japan Society of Powder and Powder Metallurgy|
|出版ステータス||Published - 1987|
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