Temperature and Stress Controlled Surface Manipulation in NiAl Nano-Layers
V.K. Sutrakar, D. Roy Mahapatra, R.V.N. Melnik
Indian Institute of Science, IN
Keywords: quantum dot array, template, phase transformation, thin film, pattern
Abstract:Quantum dot arrays with precisely controlled positions and sizes are desirable for making templates for micro-and nano-electronic devices. Numerous experimental works have shown that unguided self-assembled growth of quantum dots usually fails to realize perfectly ordered dot arrays. Our present study is focused on the development of several interesting patterned surface structures by controlling the phase transformation temperature and mechanical loading of a NiAl nano-layer. The effect of boundary conditions and thickness of the nano-layer on the formation of surface patterns are also discussed. We consider NiAl thin films of an initial Austenite (B2) phase and the results on extensive Molecular Dynamics (MD) simulations of such B2-NiAl thin films by the Embedded Atom Method (EAM) are reported. We compare energies for two different boundary conditions (i) 4-edge constrained and (ii) 2-edge constrained. Lower energy of 4-edge constrained nano-layer as compared to the 2-edge constrained is an indication that the first configuration is more stable than the second one. Further, the variation of energy with time is shown. Subsequently, the deformed shape with wrinkle pattern at a higher energy level is compared with that due to stable phase. Detailed investigation regarding stability of quantum dots on this pattern will be reported.