Infrared dynamical conductivity of the valence fluctuating alloys of CePd/sub 3/
The temperature dependent dynamical conductivity of the valence fluctuating compound CePd/sub 3/, and related Ag and Rh alloys was determined from reflectivity measurements which span three decades in the infrared. At 4K, the far-infrared absorptivity of CePd/sub 3/ increases between 5 and 15 meV to more than ten times the classical skin effect prediction, and remains enhanced to above 250 meV. The effect vanishes by 400 K and diminishes upon alloying with Ag or Rh. A new analysis shows that previous measurements with nonresonant cavity techniques underestimated the enhancement by more than a factor of three because the distribution of energy among cavity modes is not uniform for strongly absorbing samples. Separation of the dynamical conductivity into conduction and bound electron parts reveals a plasma frequency of only 2.3 eV and strongly energy dependent scattering of the conduction electrons, which is the source of the enhanced absorptivity in CePd/sub 3/. Interband transitions, observed at 0.235 eV, 0.5 eV and 1.2 eV in CePd/sub 3/, shift down uniformly on alloying with silver, indicating that all of these transitions are into the same f-derived energy level a few tenths of an eV above the fermi energy. Existing theories that produce frequency dependent scattering are inconsistent with the observed form and magnitude of the data: a quadratic increase with frequency saturating, around 22 meV (180 cm/sup -1/) at 1.1 x 10/sup 15/ s/sup -1/, sixty times its initial value.
- Research Organization:
- Cornell Univ., Ithaca, NY (USA)
- OSTI ID:
- 5338367
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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