Polar phonons and spin-phonon coupling in HgCr2S4 and CdCr2S4

Simple item page
dc.creatorRudolf, T.
dc.creatorKant, Ch.
dc.creatorMayr, F.
dc.creatorHemberger, J.
dc.creatorTsurkan, V.
dc.creatorLoidl, A.
dc.date2007-07-25
dc.date.accessioned2026-07-07T09:46:29Z
dc.date.available2026-07-07T09:46:29Z
dc.descriptionPolar phonons of HgCr2S4 and CdCr2S4 are studied by far-infrared spectroscopy as a function of temperature and external magnetic field. Eigenfrequencies, damping constants, effective plasma frequencies and Lyddane-Sachs-Teller relations, and effective charges are determined. Ferromagnetic CdCr2S4 and antiferromagnetic HgCr2S4 behave rather similar. Both compounds are dominated by ferromagnetic exchange and although HgCr2S4 is an antiferromagnet, no phonon splitting can be observed at the magnetic phase transition. Temperature and magnetic field dependence of the eigenfrequencies show no anomalies indicating displacive polar soft mode behavior. However, significant effects are detected in the temperature dependence of the plasma frequencies indicating changes in the nature of the bonds and significant charge transfer. In HgCr2S4 we provide experimental evidence that the magnetic field dependence of specific polar modes reveal shifts exactly correlated with the magnetization showing significant magneto-dielectric effects even at infrared frequencies.
dc.description8 pages, 8 figures
dc.identifierhttps://arxiv.org/abs/0707.3776
dc.identifierhttp://arxiv.org/abs/0707.3776
dc.identifierPhys. Rev. B 76, 174307 (2007)
dc.identifierdoi:10.1103/PhysRevB.76.174307
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/163545
dc.subjectStrongly Correlated Electrons
dc.titlePolar phonons and spin-phonon coupling in HgCr2S4 and CdCr2S4
dc.typetext

Files

Collections

arXiv