Spin-electron-phonon excitation in Re-based half-metallic double perovskites

A remarkable hardening (~30 cm(-1)) of the normal mode of vibration associated with the symmetric stretching of the oxygen octahedra for the Ba(2)FeReO(6) and Sr(2)CrReO(6) double perovskites is observed below the corresponding magnetic ordering temperatures. The very large magnitude of this effect...

Full description

Saved in:
Bibliographic Details
Published inPhysical review letters Vol. 108; no. 17; p. 177202
Main Authors García-Flores, A F, Moreira, A F L, Kaneko, U F, Ardito, F M, Terashita, H, Orlando, M T D, Gopalakrishnan, J, Ramesha, K, Granado, E
Format Journal Article
LanguageEnglish
Published United States 25.04.2012
Online AccessGet more information

Cover

More Information
Summary:A remarkable hardening (~30 cm(-1)) of the normal mode of vibration associated with the symmetric stretching of the oxygen octahedra for the Ba(2)FeReO(6) and Sr(2)CrReO(6) double perovskites is observed below the corresponding magnetic ordering temperatures. The very large magnitude of this effect and its absence for the antisymmetric stretching mode provide evidence against a conventional spin-phonon coupling mechanism. Our observations are consistent with a collective excitation formed by the combination of the vibrational mode with oscillations of Fe or Cr 3d and Re 5d occupations and spin magnitudes.
ISSN:1079-7114
DOI:10.1103/physrevlett.108.177202