  We have measured polarized Raman scattering spectra of the
Fe$_{1-x}$Co$_{x}$Sb$_{2}$ and Fe$_{1-x}$Cr$_{x}$Sb$_{2}$ (0$\leq x\leq $0.5)
single crystals in the temperature range between 15 K and 300 K. The highest
energy $B_{1g}$ symmetry mode shows significant line asymmetry due to phonon
mode coupling width electronic background. The coupling constant achieves the
highest value at about 40 K and after that it remains temperature independent.
Origin of additional mode broadening is pure anharmonic. Below 40 K the
coupling is drastically reduced, in agreement with transport properties
measurements. Alloying of FeSb$_2$ with Co and Cr produces the B$_{1g}$ mode
narrowing, i.e. weakening of the electron-phonon interaction. In the case of
A$_{g}$ symmetry modes we have found a significant mode mixing.

Strongly Correlated Electrons