A phase field study of morphological instabilities in multilayer thin films

Chirranjeevi, BG and Abinandanan, TA and Gururajan, MP (2009) A phase field study of morphological instabilities in multilayer thin films. In: Acta Materialia, 57 (4). pp. 1060-1067.

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Abstract

We studied the microstructural evolution of multiple layers of elastically stiff films embedded in an elastically soft matrix using a phase field model. The coherent and planar film/matrix interfaces are rendered unstable by the elastic stresses due to a lattice parameter mismatch between the film and matrix phases, resulting in the break-up of the films into particles. With an increasing volume fraction of the stiff phase, the elastic interactions between neighbouring layers lead to: (i) interlayer correlations from an early stage; (ii) a longer wavelength for the maximally growing wave; and therefore (iii) a delayed break-LIP. Further, they promote a crossover in the mode of instability from a predominantly anti-symmetric (in phase) one to a symmetric (out of phase) one. We have computed a stability diagram for the most probable mode of break-up in terms of elastic modulus Mismatch and Volume fraction. We rationalize our results in terms of the initial driving force for destabilization, and corroborate our conclusions using simulations in elastically anisotropic systems.

Item Type:	Journal Article
Publication:	Acta Materialia
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Phase field modelling;Thin films;Asaro-Tiller-Grinfeld instability;Microstructural evolution;Elastically stressed solids
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	16 Nov 2009 12:17
Last Modified:	22 Feb 2012 08:18
URI:	http://eprints.iisc.ac.in/id/eprint/19699

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