Phonon anomalies and phonon-spin coupling in oriented PbFe0.5Nb0.5O3 thin films

dc.contributorVirginia Techen
dc.contributor.authorCorrea, Margaritaen
dc.contributor.authorKumar, Amiten
dc.contributor.authorPriya, Shashanken
dc.contributor.authorKatiyar, Ram S.en
dc.contributor.authorScott, J. F.en
dc.contributor.departmentMechanical Engineeringen
dc.date.accessed2013-12-18en
dc.date.accessioned2014-02-11T13:46:00Zen
dc.date.available2014-02-11T13:46:00Zen
dc.date.issued2011-01-18en
dc.description.abstractWe present Raman data on both single-crystal and thin-film samples of the multiferroic PbFe0.5Nb0.5O3 (PFN). We show first that the number and selection rules of Raman lines are compatible with a face-centered-cubic Fm-3m structure, as is known in other ABO(3) relaxors, such as PbSc1/2Ta1/2O3. We then compare Raman data with anomalies in magnetization and the dielectric constant near the magnetic-phase-transition temperature (T-N), the diffuse ferroelectric-phase-transition temperature (T-m), and the pseudostructural-phase transition temperature (Burns temperature similar to T-B). The temperature evolution of the Raman spectra for the PFN film shows measurable changes in phonon positions, intensities, and full width at half maxima near 200, 410, and 650 K-temperatures that match well with experimentally observed T-N, T-m, and T-B, respectively. The increase in frequency with increasing temperature for the lowest-energy F-2g phonon mode is particularly unexpected. These changes suggest the transition of the crystal structure from an ordered phase to a disordered phase near T-B. The Raman study revealed phonon anomalies in the vicinity of T-m and T-N that are attributed to the dynamical behavior of polar nanoregions and spin-phonon coupling owing to its relaxor and multiferroic nature, respectively, which is well supported by dielectric and magnetic properties of the PFN thin film. Softening of the Fe-O mode was observed near the T-N. We correlate the anomalous shift of the Fe-O mode frequency with the normalized square of the magnetization sublattice; agreement with the experimental results suggests strong spin-phonon coupling near T-N owing to phonon modulation of the superexchange integral; however, the shifts in frequency with temperature are small (<3 cm(-1)).en
dc.description.sponsorshipDoD_W911NF-06-1-0183en
dc.description.sponsorshipDoE DE-FG 02-08ER46526en
dc.format.mimetypeapplication/pdfen
dc.identifier.citationCorrea, Margarita ; Kumar, Ashok ; Priya, Shashank ; et al., Jan 18, 2011. "Phonon anomalies and phonon-spin coupling in oriented PbFe0.5Nb0.5O3 thin films," PHYSICAL REVIEW B 83(1): 014302. DOI: 10.1103/PhysRevB.83.014302en
dc.identifier.doihttps://doi.org/10.1103/PhysRevB.83.014302en
dc.identifier.issn1098-0121en
dc.identifier.urihttp://hdl.handle.net/10919/25401en
dc.identifier.urlhttp://link.aps.org/doi/10.1103/PhysRevB.83.014302en
dc.language.isoen_USen
dc.publisherAmerican Physical Societyen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectferroelectromagnet pb(fe1/2nb1/2)o-3en
dc.subjectTemperatureen
dc.subjectScatteringen
dc.subjectCeramicsen
dc.subjectSpectraen
dc.subjectFielden
dc.subjectPhysicsen
dc.titlePhonon anomalies and phonon-spin coupling in oriented PbFe0.5Nb0.5O3 thin filmsen
dc.title.serialPhysical Review Ben
dc.typeArticle - Refereeden
dc.type.dcmitypeTexten
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