New insights into heat conduction in solids

Heat is generally transferred through solids by collective atom vibrations named phonons. Naturally, the phonon life time is very important for the thermal transport behavior. However, a recent study of the clathrate I Ba_7.81Au_5.33Ge_40.67 by inelastic neutron scattering revealed a different picture. Although the material is a thermal insulator, phonons showed an unusual long life time. This unusual behavior has its origin in the crystal structure allowing only a small number of phonons to form. Prior to the neutron scattering experiments, extensive crystal growth experiments were performed at the department of Chemical Metals Sciences at MPI CPfS. The following experiments were performed within an international cooperation at the Institut Laue-Langevin (ILL) in Grenoble. The better understanding of heat conductivity in cage compounds provided by these experiments will allow for a better conception of thermoelectric materials.

MB , HB / CPfS