Temperature modulation of the optical transitions involving the Fermi surface in Ag: Experimental

Thermoreflection and thermotransmission measurements were made on thin semitransparent films of Ag at about 320, 120, and 15 K in the range 3.40-4.40 eV. The results are in fairly good agreement with the theory presented in the preceding paper but show that thin metal films evaporated on amorphous substrates become strained upon cooling to low temperature. The onset of the $L_3\to L_2^{}{}_{}{}^{\prime }\left(E_F\right)$ transition is found to be at 4.03 eV, while the onset of the $L_2^{}{}_{}{}^{\prime }\left(E_F\right)\to L_1$ transition occurs at 3.87 eV.