Auteur(s): Al-Zein A., Hlinka J., Rouquette Jérôme, Hehlen B.
(Article) Publié: Physical Review Letters, vol. 105 p.017601 (2010)
Ref HAL: hal-00527762_v1
PMID 20867477
DOI: 10.1103/PhysRevLett.105.017601
WoS: 000279341400001
Exporter : BibTex | endNote
51 Citations
Résumé:
Hyper-Raman scattering experiments suggest that a splitting of the lowest F1u-symmetry mode of PbMg1/3Nb2/3O3 crystal occurs in a wide temperature range around its Burns temperature Td≈630 K. The upper-frequency component, earlier investigated by inelastic neutron scattering experiments above Td, appears to be underdamped even hundred of degrees below Td. The lower-frequency component, known below Td from far-IR spectroscopy, actually becomes underdamped above Td. This suggests that the lower-frequency mode is the “primary” polar soft mode of PbMg1/3Nb2/3O3, responsible for the Curie-Weiss behavior of its dielectric permittivity above Td.