Cobalt-doped iron oxide nanoparticles were prepared by solution combustion technique. The structural and magnetic properties of the prepared samples were also investigated. The average crystallite size of cobalt ferrite (CoFe2O4) magnetic nanoparticle was calculated using Scherrer equation, and it was found to be 16±5 nm. The particle size was measured by transmission electron microscope. This ...

Ferrite metamaterials based on the negative permeability of ferromagnetic resonance in ferrites are of great interest. However, such metamaterials face a limitation that the ferromagnetic resonance can only take place while an external magnetic field applied. Here, we demonstrate a metamaterial based on permanent magnetic ferrite which exhibits not only negative refraction but also near zero re...

In this paper, strontium ferrite (SrO.6Fe2O3) was synthesized by the sol-gel auto-combustion process. The thermal behavior of powder obtained from self-propagating combustion of initial gel was evaluated by simultaneous differential thermal analysis (DTA) and thermo gravimetric (TG), from room temperature to 1200°C. The as-burnt powder was calcined at various temperatures from 700-900°C to achi...

Electromagnetic vortices in a microwave cavity with an inserted piece of a magnetized ferrite appear due to the time-reversal symmetry breaking effect. We reveal numerically that the Poynting-vector vortices are possible in open resonant microwave structures with ferrite inclusions. We demonstrate a pair of resonances which have opposite vortex rotations at the same direction of time given by t...

κ-carbide hardening in a ferrite-austenite duplex low-density FeMnAlC steel has been investigated as a function of annealing processing within the temperature range 500−900 o C. Below 600 o C, a high hardness can be attained by the fine microstructures, e.g. the thin lamellar κ-carbides in austenite and dispersed nanosized particulate κ-carbides in ferrite. After further annealing, the alloy so...

Simultaneous vibration welding of 304 stainless steel was carried out with an eccentric circulating vibrator and a magnetic telescopic vibrator at subresonant (362 Hz and 59.3 Hz) and resonant (376 Hz and 60.9 Hz) frequencies. The experimental results indicate that the temperature gradient can be increased, accelerating nucleation and causing grain refinement during this process. During simulta...

Magnetic oxides are naturally occurring minerals. In order to understand their unique properties and their utilization in technological applications, one must fully understand the correlation between chemistry, structure, particle size and processing. Among the broad classification of magnetic oxides, the spinel ferrites gain much importance because of their low cost, high magnetic permeability...

A bainitic microstructure with fine ferrite plates (20 to 40 nm) in a matrix of high-carbon retained austenite, obtained by isothermal transformation at 200°C, was characterized with an energy-compensated optical position-sensitive three-dimensional atom probe. The average carbon concentration in the austenite was found to be 8.0±1.6 at.% and in the bainitic ferrite 1.1±0.7 at.%. The latter con...

may be described using complex shock wave analysis [ I . Fig. 1. Energy contained in rise time portion of pulse is used to reverse Recently, an appro.ximate but useful model describing this spins in ferrite transmission line. Magnetic field profile (dashed curve) phenomena was reported 121. Although some experimental in spin reversal region, as it emerges from output of line, represents • resid...

may be described using complex shock wave analysis [ I . Fig. 1. Energy contained in rise time portion of pulse is used to reverse Recently, an appro.ximate but useful model describing this spins in ferrite transmission line. Magnetic field profile (dashed curve) phenomena was reported 121. Although some experimental in spin reversal region, as it emerges from output of line, represents • resid...