Analysis of the transient behavior of nucleation in the Fe40Ni40P14B6 glass

The experimental isothermal kinetic curves for the Fe40Ni40P14B6 glass measured in the temperature range from 617 to 662 K have been analyzed with using the analytical equation derived as a combination of the integral form of Kolmogorov's equation of mass crystallization kinetics and the Kashchiev's transient nucleation model. Two free parameters of the model have been estimated: i) the crystallization time that is inversely proportional to the rates of nucleation and growth (τc) and ii) the transient nucleation time (τns). For both the times, an Arrhenius-type temperature dependence has been established, with activation energies of 38300 and 70650 K, respectively. Both the Avrami exponent, n, and the τns/τc ratio decrease as the annealing temperature rises (from 6.79 to 4.36 and from 1.47 to 0.025, respectively). This fact indicates approaching to the steady state nucleation rate. The steady state nucleation rate in the Fe40Ni40P14B6 glass estimated with using the values of growth rate available in the literature increases from 1.5 × 1016 to 1.7 × 1017 m−3s−1. The values of the crystal/liquid interfacial energy calculated within the classical model of homogeneous nucleation are 0.152-0.156 J/m2 in the temperature range investigated.