Authors: GB Song JK Liang LT Yang JR Chen GY Liu HF Yang GH Rao
Publish Date: 2003/06/05
Volume: 77, Issue: 7, Pages: 915-921
Abstract
The Pr1+xBa2xCu3O7±δ solid solution was investigated by means of Xray powder diffraction combined with Rietveld analysis A Pr123 single phase could be synthesized under Prrich conditions by sintering at 950 °C in air The solubility range of Pr1+xBa2xCu3O7±δ solid solution is 008≤x≤080 The structure of Pr1+xBa2xCu3O7±δ for 008≤x030 is orthorhombic The structure transforms into tetragonal for 030≤x≤080 To form the Pr123 single phase the Ba sites in the Pr123 structure must have partial Pr ions and the least amount is x=008 Ba ions cannot occupy the sites of Pr ions In the Pr123 structure Ca ions can replace Pr ions the highest value is x=04 in the PrBa2xCaxCu3O7±δ system under our experimental conditions However Ca ions cannot replace Ba ions The ionic radius plays a more important role than the chemical properties in the substitution between Pr Ba and Ca ions in the Pr123 structure
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