Mesoscale modeling of light transmission modulation in ceramics

We present a modeling approach for simulating and predicting spatially resolved properties of polycrystalline ceramics with coupled optical, elastic and dielectric degrees of freedom. This approach is implemented in the FERRET application, built upon the Multiphysics Object Oriented Simulation Environment (MOOSE) finite-element framework, that allows for the determination of the dependency of optical properties on polycrystalline grain orientation, size, and shape, as well as the action of externally applied electric fields and mechanical distortions. For the evaluation of optical transmission through a polycrystal we adopt a modification of the wave-retardation theory, originally developed by Raman and Viswanathan in 1955. The coupled model produces excellent agreement with experimental results obtained for polycrystalline Al2O3, Ce-doped Y3Al5O12, and ZnS which are used as test cases in this investigation, to evaluate both the visible and infrared parts of the electro-magnetic spectrum. Simulations of the optical properties modulation under different applied mechanical and electrical boundary conditions predict large changes to transmission, including switching from full transparency to opacity in some instances. The results of this investigation highlight a remarkable promise of functional nano- and micro-ceramics for a wide range of advanced engineering applications, including broad spectrum windows with high frequency transparency modulation, and multifunctional metamaterials by design. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.