Publication Type
Journal
Journal Name
Physical Review B
Publication Date
Page Number
224304
Volume
91
Issue
22
Abstract
A high-pressure study of the lattice dynamics in the filled skutterudite Eu0.84Fe4Sb12 was carried out by means
of x-ray powder diffraction and nuclear inelastic scattering. The anharmonicity of particular phonon modes was
characterized by mode and element specific Gr¨uneisen parameters. The large anharmonicity of the rattling optical
mode that is hybridized with the acoustical phonons at ambient pressure is reduced at high pressure as the phonon
modes decouple. This result suggests that anharmonic coupling between acoustic and optical phonon modes
plays a central role in the reduced thermal conductivity.
