Changing the parameters of vacancy formation and self-diffusion in various polymorphic modifications of iron

The activation parameters for various iron structures were calculated by the analytical method based on paired four-parameter Mie-Lennard-Jones interatomic interaction potential. Within framework of a single method, all processes calculated: Gibbs energy, enthalpy, entropy and volume both process electroneutral vacancy formation atom self-diffusion. isobaric temperature dependences indicated BCC FCC from T=10 to 1810 K along two isobars: P=0 10 GPa calculated. It is shown that at α-γ transition (1184 K), decrease during structure. At γ-delta (1667 increase With increasing pressure, jumps magnitude energy enthalpy increases, decreases. that, low temperatures, due quantum regularities, strongly depend temperature, in this region negative. In high region, good agreement has been obtained with experimental estimates different known literature. Keywords: vacancy, self-diffusion, potential, iron, structure, phase transition.