151-Eu Mossbauer studies on Eu(l+x)Ba(2-x)Cu(3)O(7+delta) oxide systems

Moessbauer parameters of 151Eu in Eu l+xBa2 Cu3O7+delta have been studied as a function of temperature, for x = 0.15 and x = 0.25. The areas of the absorption spectra for the two samples are almost equal. This could mean that the f-Moessbauer factor for 151Eu at the barium sites is much smaller than that for 151Eu at the rare earth sites, i.e. we only observe the spectra of the latter sites. According to this, the fits of the spectra with a single quadrupolar pattern and with two quadrupolar patterns have given equivalent chi square values.