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Electronic Structure of Nd 0.5 Y 0.5 Ba 2 Cu 3 O 7‐δ Single Crystals
Author(s) -
Hartmann A.,
Russell G. J.,
Matthews D. N.,
Cochrane J. W.
Publication year - 1996
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/(sici)1096-9918(19960916)24:9<657::aid-sia152>3.0.co;2-7
Subject(s) - orthorhombic crystal system , x ray photoelectron spectroscopy , crystallography , materials science , ion , chemistry , crystal structure , nuclear magnetic resonance , physics , organic chemistry
The new bulk, melt‐textured grown composite Nd 0.5 Y 0.5 Ba 2 Cu 3 O 7‐δ , which also forms large single crystals, has the standard high‐ T c 123 orthorhombic structure when oxygenated and a very high critical current density in a magnetic field of 0.5 T. Both of these results were not anticipated, as the Nd and Y ions are significantly different in size, while the absence of Y211 and/or Nd422 precipitates within the 123 grains indicates that a new pinning mechanism is responsible for the high J c . A possible mechanism has been attributed in part to the partial substitution of Nd 3+ in the Ba 2+ site, but to further understand this material and to further optimize its processing route for application purposes, we have carried out an XPS study of its electronic structure using cleaved surfaces of single crystals. The data obtained are analysed and discussed in terms of that found for high‐quality Re 123 single crystals where Re is either Nd or Y.