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A new approach to the melting of small particles is proposed to modify the known Pawlow’s model by taking into account the transfer of material from solid spherical particles to liquid ones through a gas phase. Thermodynamical analysis gives rise to a differential equation for the melting point Tm involving such size-dependent and temperature-dependent parameters of a material as the surface tensions σs(l), molar heat of fusion ΔHm and molar volumes vs(l). Solution of this equation has shown that all the limiting cases for size-independent situations coincide with results known in the literature and our analysis of size-dependent situations gives results close to the experimental data previously obtained by other authors for some metallic particles.

A kinetic model of reactive sputtering is proposed to modify Berg’s model by taking into account the true chemical interaction at solid surfaces of the target, substrate, and chamber wall having different temperatures. Any chemical reaction is correctly characterized by the rate constant k(T) rather than the sticking coefficient α, as it was previously done by Berg and other authors. Such a coefficient is solely inherent in the physical adsorption as an initial stage preceding the chemical interaction at the solid surfaces. Appropriate kinetic equations are derived by examining in detail the particle fluxes sputtered from the target and deposited onto the substrate and wall, as well as the surface chemical reactions. The kinetic equation for the target process has proved fully identical in form with that for the nonisothermal physical adsorption, whereas the kinetic equation for the substrate and wall processes are of a more complicated form. Analysis of the steady-state situation shows an advantage of th...