Abstract
(Bi0.93Pb0.17)2Sr1.9Ca2.05(Cu1.02 57Fe0.01)3Oy and (Tl0.74Bi0.25)(Ba0.2Sr0.8)2Ca2(Cu0.99 57Fe0.01)3Oy superconductors were synthesized and investigated by Mössbauer spectroscopy. The samples were carefully characterized by X-ray diffraction, by scanning electron microscopy in combination with energy dispersive X-ray fluorescence (EDX) and by electrical resistivity measurements. Introduction of small quantities of Fe led a modest decrease in the critical temperatures but the samples remained superconductors. EDX analysis confirmed that iron entered the superconducting phase.
The 57Fe Mössbauer spectra of these compounds could be evaluated based on two doublets. The two doublets were assigned to Fe located in the square planar fourfold oxygen coordinated Cu sites and to Fe in the square pyramidal fivefold oxygen coordinated Cu-sites in the 2223 and 1223 lattices. The Mössbauer parameters derived in this study were compared with the results obtained for (Tl,Pb)-1223 and (Hg,Pb)-1223 compounds measured earlier. Based on the combined set of data information on the different chemical bonding of the apical and basal oxygen in the square pyramids and on the layered electronic structure of these superconductors were derived.
| Original language | English |
|---|---|
| Pages (from-to) | 379 - 385 |
| Number of pages | 7 |
| Journal | Superconductor Science and Technology |
| Volume | 14 |
| DOIs | |
| Publication status | Published - Jun 2001 |
Fields of science
- 104005 Electrochemistry
- 104006 Solid state chemistry
- 104014 Surface chemistry
- 104017 Physical chemistry
- 105113 Crystallography
- 105116 Mineralogy
- 503013 Subject didactics of natural sciences
- 204 Chemical Process Engineering
- 204001 Inorganic chemical technology
- 205016 Materials testing
- 210006 Nanotechnology
- 211104 Metallurgy