Ernö Kuzmann, Wolfgang T. König, Markus Mair, Z. Homonnay, Z. Klencsár, G. Juhasz, Gerhard Gritzner,
"57Fe Mössbauer spectroscopy of (Bi,Pb)-2223 and (Tl,Bi)-1223 superconductors"
, in Superconductor Science and Technology, Vol. 14, Seite(n) 379 - 385, 6-2001, ISSN: 0953-2048, 57Fe Mössbauer spectroscopy of (Bi,Pb)-2223 and (Tl,Bi)-1223 superconductors, E. Kuzmann, W. T. König, M. Mair, Z. Homonnay, Z. Klencsar, G. Juhasz and G. Gritzner, Supercond. Sci. Techn. 14 (2001) 379 - 385
Original Titel:
57Fe Mössbauer spectroscopy of (Bi,Pb)-2223 and (Tl,Bi)-1223 superconductors
Sprache des Titels:
Englisch
Original Kurzfassung:
(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.
Sprache der Kurzfassung:
Englisch
Englische Kurzfassung:
(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.
Journal:
Superconductor Science and Technology
Volume:
14
Seitenreferenz:
379 - 385
Erscheinungsmonat:
6
Erscheinungsjahr:
2001
Notiz zum Zitat:
57Fe Mössbauer spectroscopy of (Bi,Pb)-2223 and (Tl,Bi)-1223 superconductors, E. Kuzmann, W. T. König, M. Mair, Z. Homonnay, Z. Klencsar, G. Juhasz and G. Gritzner, Supercond. Sci. Techn. 14 (2001) 379 - 385
Forschungs-