Diffuse reflection of phonons and the anomalous Kapitza resistance

Diffuse reflection of phonons and the anomalous Kapitza resistance

High-resolution time-of-flight phonon-reflection spectra in sapphire crystals are analyzed with the aid of detailed numerical calculations. It is argued that spectra from vacuum interfaces may be understood if about half the incident phonons are assumed to be reflected specularly, the remainder diffusely. A simple model of the effect on spectra of diffuse scattering is presented and compared to...

Appraisal of the Cmn/helium Kapitza Resistance

It is argued that the thermal resistance between cerium magnesium nitrate (CMN) and pure He,He containing He* impurity or dilute He in He"* can be understood in terms of the phonon bottlenecked spin-lattice resistance within the CMN and a size dependent thermal boundary resistivity. The fact that emerges is that the phonon bottleneck within the CMN is strongly dependent upon whether the CMN is ...

Phonons of the anomalous element cerium.

Many physical and chemical properties of the light rare-earths and actinides are governed by the active role of f electrons, and despite intensive efforts the details of the mechanisms of phase stability and transformation are not fully understood. A prominent example which has attracted a lot of interest, both experimentally and theoretically over the years is the isostructural γ - α transitio...

Kapitza resistance and the thermal conductivity of amorphous superlattices

REFLECTION OF PHONONS IN 4He BY NaF

The angular distribution after reflection at a cleaved NaF-liquid He interface of a collimated phonon beam incident from the helium at a grazing angle of incidence of ̂ 10° has been measured. The results suggest the existence of interface states which interact with only a part of the incident phonon spectrum. In the light of experiments which have been aarried out on the problem of phonon transm...