Effect Magneto – Optic on Ferromagnetic Nanoparticle Polymer Composite Films

Optical properties of a composite material made of ferromagnetic matel nanoparticles embedded in dielectric host are studied. A nonlinear dependence of the optical rotation on magnetic field resulting from the reorientation of nanoparticles is demonstrated. The data of optical properties finding were applied to the magneto – optic experimental data of nickel ferrite (NiFe2 O4) ferromagnetic nanoparticles embedded in polymer (PMMA) host. The magneto – optic is applied at wavelength (540 nm) and magnetic field intensity (450 m T), from result we found the affect magneto – optical on samples.

Slow and Fast Lights in Metal/Dielectric Composite of Cylindrical Nanoinclusions in Passive and Active Linear Dielectric Host Matrices

This paper presents theoretical discussions and computational numerical results obtained from the study of extreme values of the speed of light in metal/dielectric composite, where the cylindrical nanoinclusions are uniformly distributed in the linear dielectric host matrix. The results testify that, within our approach, at the region of anomalous dispersion, light can travel with a group velocity greater than the speed of light in vacuum. In a composite with passive host matrix, the light pulse is absorbed within a very small distance. The problem of absorption can be reduced considerably by using an active host matrix.

Periodic Metallo-Dielectric Structures: Electromagnetic Absorption and its Related Developed Temperatures

Multi-layer, metallo-dielectric structures (screens) have long been employed as electromagnetic band filters, either in transmission or in reflection modes. Here we study the radiation energy not transmitted or reflected by these structures (trapped radiation, which is denoted—absorption). The trapped radiation leads to hot surfaces. In these bi-layer screens, the top (front) screen is made of metallic hole-array and the bottom (back) screen is made of metallic disk-array. The gap between them is filled with an array of dielectric spheres. The spheres are embedded in a dielectric host material, which is made of either a heat-insulating (air, polyimide) or heat-conducting (MgO) layer. Electromagnetic intensity trapping of 97% is obtained when a 0.15 micron gap is filled with MgO and Si spheres, which are treated as pure dielectrics (namely, with no added absorption loss). Envisioned applications are anti-fogging surfaces, electromagnetic shields, and energy harvesting structures.

Enhanced and controllable nonlinear effects in composite with aligned gold spheroid arrays

The linear and nonlinear optical properties of composite containing aligned prolate spheroid nanoparticles embedded in a dielectric host are studied as a function of depolarization factor. It is shown that the effective third-order nonlinear susceptibility of the composite can be significantly enhanced with respect to the linear optical properties, due to a combination of varying nanoparticle shape and interparticle space. The susceptibility enhancement is up to four orders larger compared to the spherical case. The susceptibility enhancement of the host is finally comparable to the inclusion after choosing property structure parameters. The geometry-dependent susceptibility enhancement can lead to an improved figure of merit for nonlinear absorption.

Magnetic Behavior of Barium Hexaferrite Nanoparticles

An analysis of the magnetic behavior of Barium Hexaferrite nanoparticles is presented in this paper. The particles’ average size is around 200 nm. The SU-8 photoresist is used as dielectric host matrix in which the particles are embedded. The volume fraction of magnetic particles reached is around 10%. Microwave characterizations show the properties of the resulting nanocomposite. The external applied magnetic field plays the main role in orienting these magnetic particles in the composite. Coplanar CPW lines were used to investigate the magnetic material’s efficiency by its non-reciprocal effects. Magnetic nanocomposites seem promising material for future applications. Thus, higher magnetic particle volume fractions and better orientation are required.

Microwave Properties of Mechanosynthesized Fe-Paraffin Nanocomposites

The structure and microwave properties of composites consisting of paraffin as a dielectric host matrix and Fe particles as inclusions have been studied. The composites were prepared by the mechanochemical synthesis and contain 7.7% vol. concentration of the inclusions. The microwave properties were studied in 0.1 to 6 GHz frequency range. The microwave properties of the composites are shown to depend mostly on the size and shape of the inclusions, with the phase composition of the inclusions exerting only a slight effect. With decreasing the inclusions size, the low-frequency peak (300−400 MHz) attributed to the domain wall motion diminishes.