Role of varying electronic density of states in the far-infrared behavior ofV3Si

Far-infrared measurements in a thin film of ${\mathrm{V}}_3$Si at 19 K are analyzed with new expressions for the acconductivity for the case of a nonconstant electronic density of states $N\left(\epsilon \right)$. It is found that the infrared data can be fitted with a transport electron-phonon coupling function ${\alpha }_{\mathrm{tr}}^{2}F$ which is proportional to the measured phonon density of states, and with an $N\left(\epsilon \right)\ne \mathrm{const}$. Thereby, the discrepancy between the neutron scattering results and the previous analysis of the infrared behavior is resolved.