A Raman view of local lattice distortions and charge transfer in cuprates

Liarokapis, E; Lampakis, D; Palles, D; Karpinski, J; Panagopoulos, C

dc.contributor.author	Liarokapis, E	en
dc.contributor.author	Lampakis, D	en
dc.contributor.author	Palles, D	en
dc.contributor.author	Karpinski, J	en
dc.contributor.author	Panagopoulos, C	en
dc.date.accessioned	2014-03-01T01:23:30Z
dc.date.available	2014-03-01T01:23:30Z
dc.date.issued	2006	en
dc.identifier.issn	0022-3697	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/16985
dc.subject	A. Oxides	en
dc.subject	A. Superconductors	en
dc.subject	C. High pressure	en
dc.subject	C. Raman spectroscopy	en
dc.subject	D. Phonons	en
dc.subject.classification	Chemistry, Multidisciplinary	en
dc.subject.classification	Physics, Condensed Matter	en
dc.subject.other	Buckling	en
dc.subject.other	Charge transfer	en
dc.subject.other	Oxides	en
dc.subject.other	Phonons	en
dc.subject.other	Raman spectroscopy	en
dc.subject.other	Superconducting materials	en
dc.subject.other	Superconducting transition temperature	en
dc.subject.other	Chemical doping	en
dc.subject.other	Critical pressure	en
dc.subject.other	High pressure	en
dc.subject.other	Non-linear modifications	en
dc.subject.other	Crystal defects	en
dc.title	A Raman view of local lattice distortions and charge transfer in cuprates	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.jpcs.2006.05.054	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.jpcs.2006.05.054	en
heal.language	English	en
heal.publicationDate	2006	en
heal.abstract	Small changes in doping or the application of a hydrostatic pressure can induce non-linear lattice distortions, lattice instabilities, and phase separation in the cuprates. In YBa2Cu3Ox, oxygen doping above optimal induces a separation into microphases originating from a modification in the buckling of the CuO2 planes. In the same compound, the excess nominal doping by Ca creates changes in the CuO2 buckling at some critical concentrations. These are correlated with the formation of domains where the additional carriers brought by Ca remain isolated surrounded by yttrium atoms. Furthermore, it was observed that hydrostatic pressure induces non-linear modifications in the spectral characteristics of the A(g)-symmetry phonons in all cuprates studied (YBa2Cu3O6.5, YBa2Cu3Oover YBa2Cu4O8, and Bi2Sr2CaCu2O8). A coexistence of phases appears at a critical pressure where changes in the superconducting transition temperature have been detected. We have also observed similar correlations between the transition temperature and spectral modifications by chemical doping in the Raman spectra of La2-xSrxCuO4. Finally, soft modes were found in the cuprates studied, with energies scaling with the maximum transition temperature of the compound. (c) 2006 Elsevier Ltd. All rights reserved.	en
heal.publisher	PERGAMON-ELSEVIER SCIENCE LTD	en
heal.journalName	Journal of Physics and Chemistry of Solids	en
dc.identifier.doi	10.1016/j.jpcs.2006.05.054	en
dc.identifier.isi	ISI:000241089600023	en
dc.identifier.volume	67	en
dc.identifier.issue	9-10	en
dc.identifier.spage	2065	en
dc.identifier.epage	2071	en