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The nonlocal effective permittivity tensor for photonic crystals (PCs), having dielectric and metallic inclusions in the unit cell, is calculated and analyzed within the homogenization theory based on the Fourier formalism and the form-factor division approach. A method allowing us to extract the effective bianisotropic metamaterial parameters (permeability and chirality) from the wave vector dependence of the nonlocal effective dielectric response is proposed. Both the original nonlocal dielectric response parameters and the new bianisotropic metamaterial ones reproduce the photonic band structure of the artificial crystal far beyond the long wavelength limit and for a wide class of metal-dielectric structures. To calculate the optical spectra (reflection and transmission) of finite-size PC, the nonlocal homogenization approach is extended with the method of expansion into photonic bulk-modes (Bloch waves). The application of the developed theory is illustrated with well-known forms of metallic inclusions (slabs, thin wires, split-ring resonators) and experimentally confirmed with novel designs based on metallic crosses.

In this paper the possibility of obtaining thin InN films on porous InP substrates by radical-beam gettering epitaxy is considered. Porous InP prepared by electrochemical etching. On the surface of porous InP by Auger spectroscopy proved the formation of films of InN.

The nonlocal effective dynamic mass-density and stiffness tensors for a solid 3D phononic crystal having Au inclusions embedded in a Si host matrix have been calculated. The applied homogenization theory is based on the Fourier formalism and the form-factor division approach. Using the effective parameters, the phononic band structure of the homogenized elastic crystal can be described even beyond the long wavelength limit. It is found out that the effective dynamic mass-density becomes anisotropic as the frequency of the phononic modes is increased because the nonlocal metasolid response depends on the phononic-mode polarization, the shape of the inclusions, and the type of the periodic array.

Purpose: The article proposes a methodology for determining the chemical quality criterion of porous layers synthesized on the surface of semiconductors, based on taking into account the chemical parameters of the surface that can affect the properties of nanostructures. Design/methodology/approach: The chemical quality criterion was evaluated in terms of stoichiometry, stability of structures over time, uniformity of distribution over the surface, and the presence of an oxide phase. As an example, a calculation is demonstrated for the por-InP/InP structure synthesized on a mono-InP surface. The results of calculating the chemical quality criterion were evaluated using the Harrington scale to rank samples by quality level. Findings: A chemical criterion for the quality of porous layers synthesized on the surface of semiconductors has been developed. This criterion contains a set of indicators sufficient for a comprehensive assessment of the surface condition and is universal in nature. The studies carried out make it possible to reasonably approach the determination of the modes of electrochemical processing of semiconductors and open up new perspectives in the construction of a model of self-organization of a porous structure. Research limitations/implications: The chemical quality criterion does not allow evaluating the obtained nanostructures in terms of geometric parameters. Therefore, in the future, there is a need to develop a morphological quality criterion and determine a methodology for assessing a generalized quality criterion for nanostructures synthesized on the surface of semiconductors, which may include economic, environmental, technological indicators, and the like. Practical implications: Study results are expedient from a practical point of view, since they make it possible to reasonably approach the determination of the modes of electrochemical processing of semiconductors, synthesize nanostructures with predetermined properties, and create standard samples of nanomaterial composition.Originality/value: Methodology for assessing the quality of porous semiconductors by a chemical criterion has been applied for the first time in engineering science. The article will be useful to engineers, who are engaged in the synthesis of nanostructures, researchers and scientists, as well as specialists in nanometrology.