2008/10/11 by K. -Y. Choi, Kwang‐Yong Choi, D. Wulferding +7 · 1 citation
Business, Management and Accounting · Materials Science · Physics and Astronomy · #Corporate Taxation and Avoidance #Iron-based superconductors research #Rare-earth and actinide compounds #cond-mat.mtrl-sci #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.78.212503
4 pages, 4 figures
arxiv created 2008/10/11 · openalex publication_date 2008/12/08 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We report inelastic light-scattering experiments on CaFe2As2 in the temperature range of 4--290 K. In in-plane polarizations two Raman-active phonon modes are observed at 189 and 211 cm^\ensuremath-1, displaying A1g and B1g symmetries, respectively. Upon heating through the tetragonal-to-orthorhombic transition at about TS=173 K, the B1g phonon undergoes a discontinuous drop of frequency by 4 cm^\ensuremath-1, whereas the A1g phonon shows a suppression of the integrated intensity. Their linewidth increases strongly with increasing temperature and saturates above TS. This suggests (i) a first-order structural phase transition and (ii) a drastic change in charge distribution within the FeAs plane through TS.