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Series

Ames Laboratory

1973

Articles 1 - 3 of 3

Full-Text Articles in Physics

Absorptivity Of Single-Crystal Yttrium At 4.2 K, J. H. Weaver, David W. Lynch May 1973

Absorptivity Of Single-Crystal Yttrium At 4.2 K, J. H. Weaver, David W. Lynch

Physics and Astronomy Publications

Measurements of the absorptivity of single crystals of Y were made between 0.15 and 4.4 eV at 4.2 K. Polarized radiation was used with the electric vector parallel or perpendicular to the c^ axis of the crystal. The observed structures in the absorptivity were interpreted on the basis of band calculations for Sc, Re, and Gd and qualitative agreement was found between the band structures and the observed spectra.


Optical Properties Of Niobium From 0.1 To 36.4 Ev, J. H. Weaver, David W. Lynch, C. G. Olson May 1973

Optical Properties Of Niobium From 0.1 To 36.4 Ev, J. H. Weaver, David W. Lynch, C. G. Olson

Physics and Astronomy Publications

The absorptivity or reflectivity of single crystals of Nb has been measured from 0.1 to 36.4 eV. The data were Kramers-Kronig analyzed and the optical constants obtained. The absence of low-energy interband transitions has been noted, while interband effects have been observed beginning at about 1.4 eV and extending to about 19 eV. Comparisons with existing experimental data are made. Identification of some interband effects has been tentatively made from the band structure calculated by Mattheiss. The loss function has been obtained and strong resonances have been noted at 9.9 and 20.8 eV. From our ...


Optical Properties Of Single-Crystal Be From 0.12 To 4.5 Ev, J. H. Weaver, David W. Lynch, R. Rosei Apr 1973

Optical Properties Of Single-Crystal Be From 0.12 To 4.5 Ev, J. H. Weaver, David W. Lynch, R. Rosei

Physics and Astronomy Publications

Measurements of the optical absorptivity of single crystals of Be have been carried out in the energy range 0.12-4.5 eV with polarized light. The infrared absorptivity is considerably lower than previously reported. Evidence is presented for the onset of interband transitions for both polarizations beginning near 0.4 eV. A shoulder is noted in the absorptivity for E⊥cat about 1.3 eV. The absorptivity data are Kramers-Kronig analyzed and the optical constants are determined. An interpretation based on the band structure of Tripp, Everett, Gordon, and Stark is presented.