Raman and Mössbauer study of the pseudo-orthorhombic-to-tetragonal phase transition in YBa2(Cu1-xFex)3O7-δ (0.02≤x≤0.15)

Iliev, M; Atanassova, Y; Bozukov, L; Tihov, J; Hadjiev, VG; Liarokapis, E

dc.contributor.author	Iliev, M	en
dc.contributor.author	Atanassova, Y	en
dc.contributor.author	Bozukov, L	en
dc.contributor.author	Tihov, J	en
dc.contributor.author	Hadjiev, VG	en
dc.contributor.author	Liarokapis, E	en
dc.date.accessioned	2014-03-01T01:09:01Z
dc.date.available	2014-03-01T01:09:01Z
dc.date.issued	1992	en
dc.identifier.issn	09214534	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/10800
dc.subject	Phase Transition	en
dc.subject.other	Ceramic Materials	en
dc.subject.other	Spectroscopy, Mossbauer	en
dc.subject.other	Spectroscopy, Raman	en
dc.subject.other	Yttrium Compounds--Phase Transitions	en
dc.subject.other	Oxide Superconductors	en
dc.subject.other	Yttrium Barium Copper Iron Oxides	en
dc.subject.other	High Temperature Superconductors	en
dc.title	Raman and Mössbauer study of the pseudo-orthorhombic-to-tetragonal phase transition in YBa2(Cu1-xFex)3O7-δ (0.02≤x≤0.15)	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/0921-4534(92)90939-A	en
heal.identifier.secondary	http://dx.doi.org/10.1016/0921-4534(92)90939-A	en
heal.publicationDate	1992	en
heal.abstract	The polarized Raman spectra from microcrystals of YBa2(Cu1-xFex)3O7-δ (0.02≤x≤0.15) were studied in various scattering configurations allowing one to follow the variations with x of both diagonal (Ag) and non-diagonal (B2g and B3g) Raman modes. It was found that the splitting of the strongest in intensity B2g, B3g Raman pair at 210 and 300 cm-1 associated with O(4) vibrations along a and b, respectively, decreases slightly with x, thus indicating that in a microscopic scale the structure remains orthorhombic over the whole substitutional range. The Mössbauer spectra for x=0.05, 0.10, and 0.15 showed a superlinear increase of the number of five-fold oxygen-coordinated Fe-atoms at the Cu(1)-sites. This is consistent with the assumption that Fe-clusters are formed along the <110> microtwin boundaries at higher x. In this sense YBa2(Cu1-xFex)3O7-δ could be considered as a two-phase system. The observed splitting of the Ag Raman mode of Ba at x≥0.07 supports such an assumption. The Fe substitution increases the local disorder thus including additional Raman scattering of one-phonon density-of-states origin with a maximum at 580 cm-1. © 1992.	en
heal.journalName	Physica C: Superconductivity and its applications	en
dc.identifier.doi	10.1016/0921-4534(92)90939-A	en
dc.identifier.volume	191	en
dc.identifier.issue	3-4	en
dc.identifier.spage	419	en
dc.identifier.epage	428	en