2005/06/02 by T. Rudolf, K. Pucher, F. Mayr +5 · 1 citation
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic and transport properties of perovskites and related materials #Multiferroics and related materials #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.72.014450
published as Phys. Rev. B 72, 014450 (2005) · 8 pages, 6 figures
arxiv created 2005/06/02 · openalex publication_date 2005/07/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
A detailed investigation of phonon excitations and charge carrier dynamics in single crystals of Fe_1\ensuremath-xCuxCr2S4 (x=0,0.2,0.4,0.5) has been performed by using infrared spectroscopy. In FeCr2S4 the phonon eigenmodes are strongly affected by the onset of magnetic order. Despite enhanced screening effects, a continuous evolution of the phonon excitations can be observed in the doped compounds with x=0.2 (metallic) and x=0.4,0.5 (bad metals), but the effect of magnetic ordering on the phonons is strongly reduced compared to x=0. The Drude-type charge-carrier contribution to the optical conductivity in the doped samples indicates that the colossal magnetoresistance effect results from the suppression of spin-disorder scattering.