Phase separation in fully oxygenated Y1-yCayBa2Cu3Ox compounds

Liarokapis, E; Palles, D; Lampakis, D; Bottger, G; Conder, K; Kaldis, E

dc.contributor.author	Liarokapis, E	en
dc.contributor.author	Palles, D	en
dc.contributor.author	Lampakis, D	en
dc.contributor.author	Bottger, G	en
dc.contributor.author	Conder, K	en
dc.contributor.author	Kaldis, E	en
dc.date.accessioned	2014-03-01T01:22:55Z
dc.date.available	2014-03-01T01:22:55Z
dc.date.issued	2005	en
dc.identifier.issn	1098-0121	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/16721
dc.subject	Phase Separation	en
dc.subject.classification	Physics, Condensed Matter	en
dc.subject.other	barium derivative	en
dc.subject.other	calcium derivative	en
dc.subject.other	copper derivative	en
dc.subject.other	oxygen derivative	en
dc.subject.other	yttrium	en
dc.subject.other	absorption spectroscopy	en
dc.subject.other	article	en
dc.subject.other	concentration (parameters)	en
dc.subject.other	energy	en
dc.subject.other	oxygenation	en
dc.subject.other	phase separation	en
dc.subject.other	phonon	en
dc.subject.other	Raman spectrometry	en
dc.subject.other	X ray spectrometry	en
dc.title	Phase separation in fully oxygenated Y1-yCayBa2Cu3Ox compounds	en
heal.type	journalArticle	en
heal.identifier.primary	10.1103/PhysRevB.71.014303	en
heal.identifier.secondary	http://dx.doi.org/10.1103/PhysRevB.71.014303	en
heal.identifier.secondary	014303	en
heal.language	English	en
heal.publicationDate	2005	en
heal.abstract	A micro-Raman spectroscopic study has been carried out on fully oxygenated Y1-yCayBa2Cu3Ox (YBCO) compounds with y = 0.0-0.2 and oxygen concentration varying with Ca in the range (x∼6.960 and 6.995). The spectral profiles of the 4Ag and 1B1g-like symmetry phonons show minor modifications with Ca, but two modes that appear close in energy to the in-phase and the out-of-phase phonons gain intensity with the Ca substitution. The changes in the intensity of these two satellite modes with the amount of Ca are correlated with modifications in the dimpling of the CuO2 planes, as detected by extended x-ray absorption fine structure, and can be attributed to the formation of superstructures and to phase separation phenomena. The evolution of two bands in the in-phase phonon, associated in pure YBCO with local structural distortions and the coexistence of optimal and oxygen overdoped phases, remains completely independent of the Ca concentration. It appears that the Ca atoms have the tendency to be surrounded by Y atoms forming an independent nanophase of the type Y0.5Ca0.5Ba2Cu3Ox with the additional carriers from Ca not contributing to an excess doping of the system. ©2005 The American Physical Society.	en
heal.publisher	AMERICAN PHYSICAL SOC	en
heal.journalName	Physical Review B - Condensed Matter and Materials Physics	en
dc.identifier.doi	10.1103/PhysRevB.71.014303	en
dc.identifier.isi	ISI:000226735100077	en
dc.identifier.volume	71	en
dc.identifier.issue	1	en