Crystallization kinetics of CoNbZr amorphous alloys thin films

Abstract

In modes of non-isothermal and isothermal annealing, the crystallization kinetics of magnetron sputtering Co 85.5Nb 8.9Zr 5.6 amorphous alloys thin films have been investigated by differential scanning calorimetry measurements. As a result, in the case of non-isothermal crystallization, one distinct exothermic peak is observed due to the crystallization of hcp α-Co. With Kissinger method, the apparent activation energy was obtained to be 99.82 kJ mol −1. By using Deloy–Ozawa method, the local activation energy of non-isothermal crystallization was calculated. For isothermal crystallization, the Avrami exponents were determined by means of the Johnson–Mehl–Avrami equation, which are in the range of 1.19–1.37. Based on Arrhenian relationship, the local activation energy was analyzed, which yields average value E c = 88.51 kJ mol −1. Finally, the local Avrami exponent was used for discussing the details of the nucleation and growth behaviors during the isothermal crystallization.