Isothermal and non-isothermal crystallization kinetics in amorphous Ni45.6Ti49.3Al5.1 thin films

The crystallization kinetics in Ni45.6Ti49.3Al5.1 film were studied by differential scanning calorimetry through isothermal and non-isothermal approaches. The activation energy for crystallization was determined to be 374 and 280 kJ/mol by the Kissinger and the Augis & Bennett method, respectively, in non-isothermal methods. In the isothermal annealing study, the Avrami exponents were in the range of 2.78-3.80 between 793 and 823 K, suggesting that the isothermal annealing was governed by three dimensional diffusion-controlled growth for Ni45.6Ti49.3Al5.1 thin films, in which the activation energy of nucleation is higher than that of growth. In addition, the transformation rate curves of Ni45.6Ti49.3Al5.1 film were also constructed by isothermal methods. The crystallization kinetics of amorphous Ni45.6Ti49.3Al5.1 film can thus be appreciated and the transformation rate also can be employed to control the degree of crystallization.