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TT: Tiefe Temperaturen
TT 16: Posters Correlated Electrons, Measuring Devices, Cryotechnique
TT 16.51: Poster
Saturday, March 5, 2005, 11:00–16:30, Poster TU C
The electronic structure of La1−xSrxTiO3+δ — •Alexander Gössling, Reinhard Rückamp, Holger Roth, Thomas Lorenz, and Markus Grüninger — II. Physikalisches Institut, Universität zu Köln
Transition-metal oxides with orbital degeneracy have attracted a lot of interest. Their optical conductivity shows multi-peak structures in the visible und ultraviolet energy range. These excitations have been attributed to interband transitions either into the upper Hubbard band or the charge-transfer band. The spectral weight of the transitions from the lower into the upper Hubbard band sensitively depends on orbital and magnetic correlations. In this way, the physics of high (∼ eV) and low (∼ meV) energies is intimately connected.
In this context we studied the effect of hole doping on the optical conductivity of the Mott-Hubbard insulator LaTiO3 in the range of 0.7 to 6.4 eV across the metal-insulator transition by means of ellipsometry. Furthermore we compare the spectra with the data of YTiO3, having a reduced bandwidth. Supported by the DFG through SFB 608.