Title :
Compatibility of Nd and Ba in YBa/sub 2/Cu/sub 3/O/sub y/ superconductor
Author :
Tang, W.H. ; Gao, J.
Author_Institution :
Dept. of Phys., Hong Kong Univ., Hong Kong
fDate :
6/1/1999 12:00:00 AM
Abstract :
A series of samples with nominal compositions of YBa/sub 2-x/Nd/sub x/Cu/sub 3/O/sub y/ were prepared by solid state reactions and investigated by X-ray diffraction, magnetic and electrical measurements. The solubility, x, was determined to be x<0.25. It is found that the solubility of rare earth Re ions at the Ba-sites in Re/sub 1+x/Ba/sub 2-x/Cu/sub 3/O/sub y/ is strongly related to a geometric parameter, the tolerance factor t. For x<0.25, T/sub c0/ are all above 92 K. For x>0.3 T/sub c0/ drops sharply to about 84 K, and finally for x=0.5 T/sub c//sup on/ falls to 30 K and T/sub c0/ is below 10 K. Our results suggest that the small compatibility of Nd and Ba in YBa/sub 2/Cu/sub 3/O/sub y/ system does not seriously suppress the superconductivity.
Keywords :
X-ray diffraction; barium compounds; electrical resistivity; high-temperature superconductors; magnetic susceptibility; materials preparation; neodymium compounds; superconducting transition temperature; yttrium compounds; X-ray diffraction; Y(BaNd)/sub 2/Cu/sub 3/O; YBa/sub 2-x/Nd/sub x/Cu/sub 3/O/sub y/; electrical resistivity; magnetic susceptibility; solid state reaction synthesis; solubility; tolerance factor; transition temperature; Neodymium; Powders; Superconducting devices; Superconducting magnets; Superconducting materials; Superconducting transition temperature; Superconductivity; Temperature measurement; X-ray diffraction; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
