Magnetically induced variations in phonon frequencies

The long-standing question of the existence of phonon-magnetism interactions in metals is examined from first principles. Through density-functional-based linear-response calculations, we show that the phonon frequencies of fcc Ni have an explicit and appreciable dependence on its magnetic moment: the frequencies increase with the magnetic moment near the Brillouin zone center, whereas the situation becomes reversed near the zone boundary, and this behavior originates from the combined role of the spin-dependent screening due to the electrons and the effect of magnetostriction.