Lattice dynamics of FeSb 2

The lattice dynamics of FeSb2 is investigated by first-principles density functional theory calculations and Raman spectroscopy. All Raman- and infrared-active phonon modes are properly assigned. The calculated and measured phonon energies are in good agreement. We have observed strong mixing of the Ag symmetry modes, with the intensity exchange in the temperature range 210 and 260 K. The Ag mode repulsion increases by doping FeSb2 with Co, with no signatures of the electron‐phonon interaction for these modes. (Some figures may appear in colour only in the online journal)