Nucleation velocity of NaPO 3 melts

The time τ for visible crystallization of NaPO 3 melts is measured in the whole range of undercoolings from the melting temperature T m to the temperature of vitrification T g . It is shown that the time τ, needed for the appearance of a visible crystallization at high supersaturations is determined by the linear growth rate, whereas the rate of heterogeneous nucleation is the main factor, determining the experimentally measured time τ at low supersaturations. The specific surface energy σ at the melt‐crystal interface is calculated from the data on nucleation velocity in the vicinity of T m and the temperature dependences of both heterogeneous and homogeneous nucleation velocity for NaPO 3 melts are constructed. It is concluded that at normal cooling rates only nucleation, initiated by active crystallized cores could be observed for NaPO 3 .