Temperature-dependent phonon spectra of magnetic random solid solutions

Abstract

A first-principles-based method for computing phonons of magnetic random solid solutions including thermal magnetic fluctuations is developed. The method takes fluctuations of force constants (FCs) due to magnetic excitations as well as due to chemical disorder into account. The developed approach correctly predicts the experimentally observed unusual phonon hardening of a transverse acoustic mode in Fe-Pd an Fe-Pt Invar alloys with increasing temperature. This peculiar behavior, which cannot be explained within a conventional, harmonic picture, turns out to be a consequence of thermal magnetic fluctuations.

References in corpus (8)

• Magnetic-induced phonon anisotropy in ZnCr${}_2$O${}_4$ from first principles
• Structural stability and thermodynamics of CrN magnetic phases from ab initio and experiment
• Element-resolved thermodynamics of magnetocaloric LaFe${}_{13-x}$Si${}_x$
• Mode-decomposition based on crystallographic symmetry in the band-unfolding method
• Electronic correlations determine the phase stability of iron up to the melting temperature
• Phonon softening in paramagnetic bcc Fe and relationship with pressure-induced phase transition
• Phonon broadening from supercell lattice dynamics: random and correlated disorder
• Brillouin zone unfolding method for effective phonon spectra

Cited by in corpus (4)

• Ab initio vibrational free energies including anharmonicity for multicomponent alloys
• Prediction of the Curie temperature considering the dependence of the phonon free energy on magnetic states
• Unfolding the complexity of quasi-particle physics in disordered materials
• Effect of the electronic charge gap on LO bond-stretching phonons in undoped La${}_2$CuO${}_4$ calculated using LDA+U