Raman spectroscopic evidence of lattice effects across the phase diagram of La2-xSrxCuO4

Liarokapis, E; Siranidi, E; Lampakis, D; Conder, K; Panagopoulos, C

dc.contributor.author	Liarokapis, E	en
dc.contributor.author	Siranidi, E	en
dc.contributor.author	Lampakis, D	en
dc.contributor.author	Conder, K	en
dc.contributor.author	Panagopoulos, C	en
dc.date.accessioned	2014-03-01T01:29:04Z
dc.date.available	2014-03-01T01:29:04Z
dc.date.issued	2008	en
dc.identifier.issn	17426588	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/19113
dc.subject	Phase Diagram	en
dc.title	Raman spectroscopic evidence of lattice effects across the phase diagram of La2-xSrxCuO4	en
heal.type	journalArticle	en
heal.identifier.primary	10.1088/1742-6596/108/1/012023	en
heal.identifier.secondary	http://dx.doi.org/10.1088/1742-6596/108/1/012023	en
heal.identifier.secondary	012023	en
heal.publicationDate	2008	en
heal.abstract	The doping and temperature dependence of the Raman spectra of high-quality La2-xSrx16,18CuO4 polycrystalline compounds with x0.0-0.3 have been investigated. The spectral characteristics of the soft phonon that appears in the (zz) polarization spectra of the LTO phase show an abnormal behaviour close to Néel transition temperature for x0.0 (in the temperature range 285-305K) and for x0.015 (in the range 77-100K), indicating an apparent coupling of the lattice to the spin ordering. The isotopic shift of the soft mode deviates from the mass harmonic law at all temperatures and this deviation increases substantially for T>175K towards room temperature. In the other scattering polarization (xx or yy), certain new bands at ∼150 cm-1, ∼280 cm-1, and ∼370 cm-1 appear mainly at low temperatures and in the superconducting doping region 0.03<x<0.27. From the study of the effects of the oxygen isotopic substitution, the possible reduction of symmetry, the doping, and the temperature dependence, the new modes have been assigned to specific IR phonons, which are activated in the Raman spectra from the local breaking of the inversion symmetry. © 2008 IOP Publishing Ltd.	en
heal.journalName	Journal of Physics: Conference Series	en
dc.identifier.doi	10.1088/1742-6596/108/1/012023	en
dc.identifier.volume	108	en
dc.identifier.issue	1	en