Abstract
The room temperature magnetocaloric material MnFe4Si3 was investigated with nuclear inelastic
scattering (NIS) and resonant ultrasound spectroscopy (RUS) at di erent temperatures and applied
magnetic fields in order to assess the in
uence of the magnetic transition and the magnetocaloric
effect on the lattice dynamics. The NIS data give access to phonons with energies above 3 meV,
whereas RUS probes the elasticity of the material in the MHz frequency range and thus low energy,
~5 neV, phonon modes. A significant in
uence of the magnetic transition on the lattice dynamics
is observed only in the low energy region. MnFe4Si3 and other compounds in the Mn5-xFexSi3
series were also investigated with vibrating sample magnetometry, resistivity measurements and
Moessbauer spectroscopy in order to study the magnetic transitions and to complement the obtained
results on the lattice dynamics.
