OPTICAL PROPERTIES OF THE ALPHA PHASE ALLOYS, AGZN AND AGCD.
FRANKFORD ARSENAL PHILADELPHIA PA PITMAN-DUNN RESEARCH LABS
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Reflectance measurements at near-normal incidence were performed on chemically polished, annealed, polycrystalline samples of the alloys AgZn and AgCd. Data was obtained for pure silver and for alloy samples with 2.5, 5.0, 10.0, 20.0 and 30.0 percent IIB atom concentration. A dual beam vacuum reflectometer built in the Solid State Physics Laboratory at Temple University electron volts at temperatures of 110K, 295K, and 400K with a precision of 2 of measured reflectance. The dielectric constants, the coefficients 4piklampda, and the energy loss functions were computed by the KramersKronig method. The results presented graphically in the interval from 2 e.v. to 7 e.v. relate mainly to interband absorption. The trends of the dielectric constants with either zinc or cadmium concentration are basically similar. The principle epsilion sub 2 peak of silver at 4.0 e.v. moves to higher energies with increase of IIB atom concentration. A secondary peak, observed only in the alloys, moves to lower energies. Transitions probably occur in the alloys from an underlying d band to the Fermi surface and also from Fermi surface up to the s band. Trends of the epsilion sub 2 peaks with concentration of zinc or cadmium follow an elementary rigid band model.