Lattice dynamics and thermal transport in multiferroic CuCrO2

Journal Article (Journal Article)

Inelastic neutron and x-ray scattering measurements of phonons and spin waves were performed in the delafossite compound CuCrO2 over a wide range of temperature, and complemented with first-principles lattice dynamics simulations. The phonon dispersions and density of states are well reproduced by our density functional calculations, and reveal a strong anisotropy of Cu vibrations, which exhibit low-frequency modes of large amplitude parallel to the basal plane of the layered delafossite structure. The low frequency in-plane modes also show a systematic temperature dependence of neutron and x-ray scattering intensities. In addition, we find that spin fluctuations persist above 300 K, far above the Néel temperature for long-range antiferromagnetic order, TN≃24K. Our modeling of the thermal conductivity, based on our phonon measurements and simulations, reveals a significant anisotropy and indicates that spin fluctuations above TN constitute an important source of phonon scattering, considerably suppressing the thermal conductivity compared to that of the isostructural but nonmagnetic compound CuAlO2.

Full Text

Duke Authors

Cited Authors

  • Bansal, D; Niedziela, JL; May, AF; Said, A; Ehlers, G; Abernathy, DL; Huq, A; Kirkham, M; Zhou, H; Delaire, O

Published Date

  • February 9, 2017

Published In

Volume / Issue

  • 95 / 5

Electronic International Standard Serial Number (EISSN)

  • 2469-9969

International Standard Serial Number (ISSN)

  • 2469-9950

Digital Object Identifier (DOI)

  • 10.1103/PhysRevB.95.054306

Citation Source

  • Scopus