2010/03/12 by Zhi-Feng Huang, K. R. Elder, Ken Elder
Engineering · Materials Science · Physics and Astronomy · #Aluminum Alloy Microstructure Properties #Amplitude #Composite material #Condensed matter physics #Elasticity (physics) #Epitaxy #Fluid Dynamics and Thin Films #Instability #Materials science #Mechanics #Mesoscopic physics #Nanotechnology #Optics #Physics #Scaling #Solidification and crystal growth phenomena #Surface energy #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.81.165421
published as Phys. Rev. B 81, 165421 (2010) · 16 pages, 10 figures; to be published in Phys. Rev. B
arxiv created 2010/03/12 · openalex publication_date 2010/04/14 · arxiv updated 2015/05/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Morphological properties of strained epitaxial films are examined through a mesoscopic approach developed to incorporate both the film crystalline structure and standard continuum theory. Film surface profiles and properties, such as surface energy, liquid-solid miscibility gap, and interface thickness are determined as a function of misfit strains and film elastic modulus. We analyze the stress-driven instability of film surface morphology that leads to the formation of strained islands. We find a universal scaling relationship between the island size and misfit strain which shows a crossover from the well-known continuum elasticity result at the weak strain to a behavior governed by a ``perfect'' lattice relaxation condition. The strain at which the crossover occurs is shown to be a function of liquid-solid interfacial thickness, and an asymmetry between tensile and compressive strains is observed. The film instability is found to be accompanied by mode coupling of the complex amplitudes of the surface morphological profile, a factor associated with the crystalline nature of the strained film but absent in conventional continuum theory.