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 |
|