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We present a new mechanism to realize broadband transmission (BT) at near infrared in a dual-layer metallic-silver-grating structure with a silicon nitride dielectric spacer. The physical mechanism is ascribed to the partial degeneracy between the first-order magnetic polariton (MP1) mode supported in the thin dielectric spacer and the Fabry-Pérot-like resonant modes supported in the gratings' slits. With parameters optimized, high transmittance up to 85% with full-width-at-half-maximum bandwidth of 64% near 1.9 μm can be realized for TM-polarized light. Moreover, the BT can be maintained in a large range of oblique incident angles from 0° to 30°. In another word, the BT is capable of not only collimated beams but also noncollimated incident lights. Moreover, the high-transmission window can be tuned in the IR spectrum region by modulating the metallic gratings' thicknesses. [ABSTRACT FROM PUBLISHER]

In this study, we propose a process to prepare Mn–Zn ferrite powder, using oxides of manganese and zinc extracted from used dry batteries, and ferrous chloride solution from waste steel pickling liquor. The hydrothermal process was used to convert the starting raw materials into Mn–Zn ferrite powder. This powder revealed the formation of cubic ferrite with a saturation magnetization ( Ms) of 58.8 emu/g and an intrinsic coercive force ( Hc) of 3.8 Oe. The average lattice thermal expansion coefficient αa (200°–500°C) of this Mn–Zn ferrite powder was 14.14 × 10−6 K−1. The toroidal specimen sintered at 1300°C in a controlled oxygen atmosphere presented a flat profile of initial permeability (μi) of 2150–2200, in the frequency range 0.1–20 kHz, which allows its use in magnetic applications. This useful technology, combined with environment and materials engineering, can promote the recycling of dry batteries and contribute to the preservation of the earth. Moreover, this technology can also decrease the cost of disposal of the used dried batteries and waste steel pickling liquor. [ABSTRACT FROM AUTHOR]

Using density functional theory, the electronic structures, lattice constants, formation energies, and optical properties of AlxGa1−xN are determined with Al component content x in a range from 0 to 1. As x increases, the lattice constants decrease in e-exponential form, and the band gap increases with a band bending parameter b = 0.3954. The N–Al interaction force in the (0001) direction is greater than the N–Ga interaction force, while the N–Al interaction force is less than the N–Ga interaction force in the () direction. The formation energies under different Al component content are negative and increase with Al component content increasing. The static dielectric function decreases, the absorption edge has a blue shift, and the energy loss spectrum moves to high energy with the Al component content increasing. [ABSTRACT FROM AUTHOR]

We propose a metasurface which consists of three conductive layers separated by two dielectric layers. Each conductive layer consists of a square array of square loop apertures, however, a pair of corners of each square metal patch surrounded by the square loop apertures have been truncated, so it becomes an orthotropic structure with a pair of mutually perpendicular symmetric axes u and v. The simulated results show that the metasurface can be used as a wideband transmission-type polarization converter to realize linear-to-circular polarization conversion in the frequency range from 12.21 GHz to 18.39 GHz, which is corresponding to a 40.4% fractional bandwidth. Moreover, its transmission coefficients at x- and y-polarized incidences are completely equal. We have analyzed the cause of the polarization conversion, and derived several formulas which can be used to calculate the magnitudes of cross- and co-polarization transmission coefficients at y-polarized incidence, together with the phase difference between them, based on the two independent transmission coefficients at u- and v-polarized incidences. Finally, one experiment was carried out, and the experiment and simulated results are in good agreement with each other. [ABSTRACT FROM AUTHOR]