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Energy Spectrum of Vacancies and Nanobubbles in Condensed Matter and Crystal Melting

par Caroline CHAMPENOIS - publié le

séminaire du laboratoire
mercredi 6 avril à 14:00, service 361 du campus Saint-Jérôme

Alexey Khrapak
Joint Institute for High Temperatures, Moscow, Russia

abstract :

Many properties of crystals near melting are determined by presence of vacancies. First, this concerns the processes of the self-diffusion, the diffusion of impurities, the ion mobility, etc. Vacancies also influence on the specific heat and volume thermal expansion of crystals. Many attempts to construct the vacancy model of melting are known. The energy of the vacancy formation is the most important characteristic of the vacancies. In the present work, the quantized energy spectrum of the oscillating spherical voids in solids and liquids is calculated within the continuum matter model. It is suggested that the ground state of the oscillating void in solid corresponds to the vacancy in real crystals. The dependence of the vacancy formation energy on the shear modulus, density, pressure and surface tension is determined. The obtained results are used to estimate properties of vacancies in solid argon along the melting line down to extremely high pressures. It is shown that nanobubbles in liquid melts preserve main properties of vacancies in solids. Obtained result may be important for development the vacancy or hole theory of melting.

contact : Sergey Khrapak

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