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dc.contributor.author | Klimin S. | |
dc.contributor.author | Kuzmenko A. | |
dc.contributor.author | Popova M. | |
dc.contributor.author | Malkin B. | |
dc.contributor.author | Telegina I. | |
dc.date.accessioned | 2018-09-18T20:20:55Z | |
dc.date.available | 2018-09-18T20:20:55Z | |
dc.date.issued | 2010 | |
dc.identifier.issn | 1098-0121 | |
dc.identifier.uri | https://dspace.kpfu.ru/xmlui/handle/net/138953 | |
dc.description.abstract | We present infrared spectra of Gd2 BaNiO5, which is isostructural to a prototype S=1 Haldane compound Y2 BaNiO 5 containing Ni2⊃+ chains, in the spectral range 2 meV-0.55 eV. Unlike Y2 BaNiO5, the studied compound contains magnetic rare-earth sublattices and orders antiferromagnetically at TN =58 K. Detailed information on optical phonons is given. Temperature dependences of frequencies and half widths for the two lowest-frequency phonons polarized along the Ni-chain direction evidence the interaction of these lattice vibrations with magnetic excitations. With the help of lattice-dynamics calculations, we find relative displacement vectors of ions for all the phonon modes and use them to discuss the mechanism of phonon-magnon interaction. The optical spectra exhibit a broad absorption continuum for radiation polarized along the chains, probably of magnetic origin, gradually decreasing with lowering temperature. A new mode at about 30 cm⊃-1 polarized along the chains (a axis) emerges below ∼150 K. A midinfrared absorption peak at 1306 cm⊃-1 (0.16 eV) is observed and found to sharpen and shift significantly at TN. We argue that it can be attributed to a phonon-assisted magnetic absorption and discuss its nature in the framework of the Lorenzana-Sawatzky-Eder model. © 2010 The American Physical Society. | |
dc.relation.ispartofseries | Physical Review B - Condensed Matter and Materials Physics | |
dc.title | Infrared study of lattice and magnetic dynamics in a spin-chain compound Gd2 BaNiO5 | |
dc.type | Article | |
dc.relation.ispartofseries-issue | 17 | |
dc.relation.ispartofseries-volume | 82 | |
dc.collection | Публикации сотрудников КФУ | |
dc.source.id | SCOPUS10980121-2010-82-17-SID78649709909 |