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AM: Magnetismus

AM 14: Magnetowiderstand I: Manganate

AM 14.4: Vortrag

Mittwoch, 29. März 2000, 15:00–15:15, H10

Optical conductivity of Pr_0.65Ca_0.28Sr_0.07MnO₃ — •J. Sichelschmidt^1,2, F. Mayr¹, A. Loidl¹, and A. A. Mukhin³ — ¹Experimentalphysik V,Universität Augsburg, D-86135 Augsburg — ²Max-Planck-Institut für Chemische Physik fester Stoffe, 01187 Dresden — ³General Physics Institute, Russian Academy of Sciences, 105835 Moscow, Russia

We have investigated the optical conductivity of the charge-ordered perovskite Pr_0.65Ca_0.28Sr_0.07MnO₃ for frequencies between 5 meV and 6 eV and temperatures between 5 K and 295 K. The results are interpreted in terms of polaronic effects. Below 100 K a broad mid-infrared band appears and indicates enhanced polaron resonance along with a considerable shift of spectral weight from the near-infrared region into the mid-infrared region. Additional phonon modes below the charge ordering temperature T_CO=210 K indicate charge order driven lattice distortions.