Activation energies for crystal nucleation and growth in amorphous alloys

Abstract

A new method to determine the activation energies for crystal nucleation and growth ( E n and E g) during crystallization of amorphous alloys is developed. The activation energy for crystallization at a certain stage, i.e. the local activation energy E c( x), is obtained by the use of the Arrhenius relation. According to the nucleation and growth processes at different stages revealed by measurement of the local Avrami exponent, the activation energies for nucleation and growth are obtained. Values of E n and E g are obtained using this method in a NiP glass. The variation of E n and E g in the pre-annealed NiP glasses by means of a new crystallization mechanism is also demonstrated and discussed.