https://doi.org/10.1140/epjb/e2005-00265-5
Optical investigations of the clathrate α-Eu8Ga16Ge30
1
Max-Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
2
Department of Structural Molecular Science, The Graduate University for
Advanced Studies, Okazaki 444-8585, Japan
3
UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
Corresponding author: a sichelschmidt@cpfs.mpg.de
Received:
4
February
2005
Revised:
7
June
2005
Published online:
18
August
2005
We performed measurements of the optical reflectivity in the energy range 0.007–30 eV on the clathrate-VIII type compound α-Eu8Ga16-xGe30x in order to investigate its electronic band structure. The very low charge carrier concentration as well as ferromagnetic ordering of the divalent Eu ions below 10.5 K characterize the spectra at photon energies below ~0.4 eV in accordance with the results of band structure calculations. Disorder induced bound states have been identified to affect the optical conductivity at energies between 10 and 100 meV.
PACS: 78.20.-e – Optical properties of bulk materials and thin films / 72.15.-v – Electronic conduction in metals and alloys
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005