2002/12/31 by A. B. Souchkov, J. R. Simpson, H. D. Drew +9 · 2 citations
Materials Science · Physics and Astronomy · #Anomaly (physics) #Antiferromagnetism #Condensed matter physics #Dielectric #Magnetic and transport properties of perovskites and related materials #Multiferroics and related materials #Phonon #Physics #Polaron #Solid-state spectroscopy and crystallography #Superexchange #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.91.027203
4 pages, 4 figures, Phys. Rev. Lett. accepted
arxiv created 2003/06/23 · openalex publication_date 2003/07/10 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We have measured the optical conductivity of single crystal LuMnO3 from 10 to 45 000 cm^\ensuremath-1 at temperatures between 4 and 300 K. A symmetry allowed on-site Mn d\mathrm\text\ensuremath-d transition near 1.7 eV is observed to blueshift (\ensuremath∼0.1 eV) in the antiferromagnetic state due to Mn--Mn superexchange interactions. Similar anomalies are observed in the temperature dependence of the TO phonon frequencies which arise from spin-phonon interaction. We find that the known anomaly in the temperature dependence of the quasistatic dielectric constant ϵ0 below TN\ensuremath∼90 K is overwhelmingly dominated by the phonon contributions.