Phonon Resonances Induced by Pb in KCl Studied by Means of Thermal Conductivity and Ionic Thermocurrent Techniques
In order to study the evolution of Suzuki-like phase occlusions in KClPb (1), (2), by thermal conductivity measurements at low temperatures, we have to consider the phonon interactions with divalent ions Pb2+. These interactions were studied many times (3) and theoretical models were proposed. One model is based on one-phonon scattering due to the mass defect (4) with an extension proposed by M. WAGNER (5) to include two-phonon interactions. A second is based on one-phonon scattering due to force constant changes in the presence of a vacancy (6). In (3) J.W. SCHWARTZ et al. concluded that phonon scattering is mainly due the cationic vacancy; the divalent ion acts when its size differs from that of the host ion. Nevertheless they do not exclude the possibility of two-phonon processes as treated by M. WAGNER (5).
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