Mechanisms of amorphous-phase-dependent grain growth in two-phase nanocomposite films: A Monte Carlo analysis

Monte Carlo calculations of the grain growth in two-phase nanocomposite films with microstructures comprising of nanocrystalline (n) and amorphous (a) phases are presented based on a modified Q -state Potts model. The mechanisms of amorphous-phase-volume-fraction- (Va) -dependent grain growth are observed by analyzing the microstructure evolution. The results show that with Va values increasing to a critical value of 23%, the grain growth transforms from a n-n -grain boundary (GB)-curvature-driven growth to the a-n -GB-curvature-driven growth. The driving force for the transition is caused by the energy difference exerted on nn or an boundaries. With further increasing Va, nanograins are completely surrounded by amorphous matrices and the diffusion-controlled growth mode driven by the difference between a-n -interfacial energies and n-n -boundary energies has been found. The homogeneity of the grain growth in the nanocomposite films with different Va values is also discussed. © 2008 American Institute of Physics.