Lattice dynamics and thermal transport in multiferroic CuCrO2

Dipanshu Bansal, Jennifer L. Niedziela, Andrew F. May, Ayman Said, Georg Ehlers, Douglas L. Abernathy, Ashfia Huq, Melanie Kirkham, Haidong Zhou, Olivier Delaire

Research output: Contribution to journalArticlepeer-review

22 Scopus citations

Abstract

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.

Original languageEnglish
Article number054306
JournalPhysical Review B
Volume95
Issue number5
DOIs
StatePublished - Feb 9 2017

Fingerprint

Dive into the research topics of 'Lattice dynamics and thermal transport in multiferroic CuCrO2'. Together they form a unique fingerprint.

Cite this