Regensburg 2004 – wissenschaftliches Programm

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MA: Magnetismus

MA 11: Magnetische Materialien

MA 11.5: Vortrag

Dienstag, 9. März 2004, 11:15–11:30, H22

Investigation of intra- and inter-atomic mechanisms in La_1−xBa_xMnO₃: A combined x-ray spectroscopic study — •Karsten Kuepper¹, Manfred Neumann¹, Vadim Galakhov², Kevin Prince³, Maurizio Matteucci⁴, and Mihaela Falub⁵ — ¹Universität Osnabrück, FB Physik, Barbarastr. 7, 49069 Osnabrück — ²Institute of Metal Physics,Russian Academy of Sciences - Ural Division, 620219 Yekaterinburg, Russia — ³Sincrotrone Trieste, in Area Science Park, Basovizza (Trieste), Italy — ⁴Institute of Condensed Matter, National Research Council c/o Sincrotrone Trieste, Italy — ⁵Paul Scherrer Inst., Swiss Light Source, WSLA-R 226, CH-5232 Villingen, Switzerland

The electronic properties of the colossal magneto resistance (CMR) compounds La_1−xBa_xMnO₃ (0 ≤ x ≤0.55) are investigated by a detailed spectroscopic study. A combination of different techniques, namely x-ray photoelectron spectroscopy (XPS), x-ray emission spectroscopy (XES), x-ray absorption spectroscopy (XAS) and resonant inelastic x-ray scattering (RIXS), is used to reveal a detailed picture of the electronic structure in the presence of Ba doping in different concentrations. The results are compared with available theory. The valence band is dominated by La 4d, Mn 3d and O 2p states, and strong hybridization between Mn 3d and O 2p states is present over the whole range of Ba concentration. XAS spectra indicate that the hole doping leads to mixed Mn 3d - O 2p states. Furthermore, RIXS at the Mn L edge probed d−d transitions between the Mn d bands as well as transitions between strongly hybridized Mn 3d - O 2p states.