First-order Raman scattering inBi1−xSbxalloys

First-order Raman spectra are reported for the entire composition range of ${\mathrm{Bi}}_{1-x}{\mathrm{Sb}}_x$ alloys. The results on thin sputtered films differ from the low-concentration extrapolations of Zitter and Watson indicating more complex mode behavior. An increase in the frequency of the Bi-derived $E_g$ mode with $x$ suggests the influence of increased covalency with alloying.