Lattice dynamics in the itinerant helical magnet MnSi

The phonon dispersion relations in MnSi were measured using inelastic neutron scattering. At the same time, calculations of the phonon spectra of MnSi were carried out in the framework of density functional theory in the local density and the generalized gradient approximations. The calculations match most of the phonon modes in the frequency range up to 40 meV. The phonon density of states obtained on the basis of the phonon dispersion was used to estimate the lattice contribution to the specific heat of MnSi.