Melting as an Instability of Crystal Structure with respect to Transverse Acoustic Wave, Quasi-Harmonic Approach |
A. Czachor
National Center for Nuclear Research, Ĺwierk, 05-400 Otwock, Poland |
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It is suggested that the precursor of melting in some crystals can be a macroscopic shear deformation such as the transverse sound wave. This hypothesis is examined basing on the quasi-harmonic approach to lattice dynamics within the two-body ion-ion concept of interaction in metals. One finds that due to the temperature induced modification of effective ion-ion interaction appearing in the quasi-harmonic approximation the crystal ceases to support propagation of transverse sound waves when its temperature approaches a certain critical temperature Tcr, understood here to be the melting temperature Tm. |
DOI: 10.12693/APhysPolA.122.365 PACS numbers: 64.70.dj |