Binding Strength and Oxygen Coordination of the Fe Sites in High TC GdBa2 Cu3O7—δ
- Received Date: 1900-01-01
- Accepted Date: 1900-01-01
- Available Online: 1993-11-05
Abstract: The GdBa2(Cu1-xFex)3O7—δ system with x=0.005-0.001 and various oxygen concentrations was investigated by 57Fe-Mossbauer spectroscopy in temperature range 20K to 300K.The spectra of the orthorhombic phase were analyzed with four quadrupole doublets.Three of them were attributed to substitutional Cu(1) sites and one (with the smallest quadrupole splitting)to the substitutional Cu(2) site.From an analysis of temperature dependence of the relative site intensities,different local Debye temperature for the Cu(1) sites were derived.Highly texturized absorbers were investigated to study the polarization dependence of the four quadrupole doublets.Measurements at the magic angle gave evidence for a vibrational anisotropy (Goldanskii-Karyagineffect) of the Cu(1) sites.The Cu(1) site with the largest quadrupole splitting exhibited the lowest Debye temperature and the largest vibrational anisotropy.





Abstract
HTML
Reference
Related
PDF












DownLoad: