Raman study of phonons in CaMn7O12 : effects of structural modulation and structural transition
dc.contributor.author | Iliev, Milko N. | pt_BR |
dc.contributor.author | Hadjiev, Viktor G. | pt_BR |
dc.contributor.author | Gospodinov, Marin | pt_BR |
dc.contributor.author | Nikolova, Rositsa Petrova | pt_BR |
dc.contributor.author | Abrashev, Miroslav Vergilov | pt_BR |
dc.date.accessioned | 2014-11-20T02:15:42Z | pt_BR |
dc.date.issued | 2014 | pt_BR |
dc.identifier.issn | 1098-0121 | pt_BR |
dc.identifier.uri | http://hdl.handle.net/10183/107173 | pt_BR |
dc.description.abstract | Polarized Raman spectra of oriented CaMn7O12 single crystals have been studied in a broad temperature range (5–500 K) covering the crystallographic, ferroelectric, and magnetic transitions. From the spectra obtained at room temperature (RT) 10 out of the total 12 Raman active 6Ag + 6Eg modes of the trigonal R¯3 phase have been identified and assigned to definite atomic motions in close comparison to results of lattice-dynamics modeling. With the decrease in temperature below 250 K some Raman bands split, and additional spectral features, not expected for the R¯3 structure, arise well above the magnetic transitions near 90 and 50 K. Their appearance, however, correlateswith the transformation due to incommensurate structural modulation revealed by recent x-ray and neutron-diffraction studies. As temperature increases above RT the intensity of the Raman lines strongly decreases, and entering the high-temperature Im¯3 phase the spectrum transforms its shape to that expected for a structure with disordered Jahn-Teller distortions. | en |
dc.format.mimetype | application/pdf | |
dc.language.iso | eng | pt_BR |
dc.relation.ispartof | Physical review. B, Condensed matter and materials physics. Woodbury. Vol. 89, no. 21 (June 2014), 214302, 6 p. | pt_BR |
dc.rights | Open Access | en |
dc.subject | Espectros raman | pt_BR |
dc.title | Raman study of phonons in CaMn7O12 : effects of structural modulation and structural transition | pt_BR |
dc.type | Artigo de periódico | pt_BR |
dc.identifier.nrb | 000938446 | pt_BR |
dc.type.origin | Estrangeiro | pt_BR |
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