Crystallization processes in bicomponent thin film depositions: towards a realistic kinetic Monte Carlo simulation

The kinetic Monte Carlo (KMC) method is a powerful and simple tool to simulate the growth of thin films by deposition. However, one of its major drawbacks is the artificial order induced by the use of regular lattices. An algorithm that mimics the crystallization processes in bi-component thin film depositions via a novel KMC approach is presented in this work. This new algorithm, named GEM-CA (Geometrical Energy Modification- Crystallization Algorithm), modifies the hopping energy barrier depending on the geometrical configuration of the atoms surrounding one particular position. The novel approach allows obtaining amorphous, crystalline and mixed structures (i.e. nanocomposites), depending solely on the synthesis parameters. In addition, we have developed a method for the analysis of deposited structures based on their degree of order. The influence of different deposition parameters such as temperature or composition is discussed in detail. GEM-CA reproduces experimentally observed trends of bicomponent film deposition.The financial support of Portuguese Foundation of Science and Technology (FCT, its acronym in Portuguese), under the project number IF/00671/2013 is gratefully acknowledged. This work has been partially funded by Spanish MCYT FPU program. We are especially grateful to Dr. J.C. Sánchez-López and Dr. A. Fernández for scientific discussions.