Dresden 2003 – wissenschaftliches Programm

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MA: Magnetismus

MA 30: Spinabh
ängige Transportph
änomene II

MA 30.9: Vortrag

Freitag, 28. März 2003, 12:45–13:00, HSZ/401

Effects of Magnetic Ordering in Lanthanides on the Optical Conductivity in the Far- and Mid-Infrared Spectral Range — •Peter Weber and Martin Dressel — 1. Physikalisches Institut, Universität Stuttgart

Rare earth metals (Lanthanides) like holmium form magnetic layers below certain ordering temperatures. Their magnetic moments are localized at the lattice sites. Ordering strongly affects the scattering rate of the surrounding conduction electrons i.e. the dc-resistivity. Furthermore the local moments polarize these electrons, which removes the degeneracy of the exchange splitting. Not much is know about the response of such systems to high-frequency ac-fields. The measurements are carried out in the infrared spectral range from 10 1/cm to 10000 1/cm (1.2 meV to 1.2 eV). Bulk single crystals as well as evaporated films are examined. For thin films the measurement of absorption and phase change then yields the frequency dependent complex optical parameters without using the Kramers Kronig relation.