Mn–Zn ferrite powders (Mn0.5Zn0.5Fe2O4) were prepared by the nitrate–citrate auto-combustion method and subsequently annealed in air or argon. The effects of heat treatment temperature on crystalline phases formation, microstructure and magnetic properties of Mn–Zn ferrite were investigated by X-ray diffraction, thermogravimetric and differential thermal analysis, scanning electron microscopy a...

There has been a surge of interest in the subwavelength confinement of electromagnetic fields. It is well known that, in optics, subwavelength confinement can be obtained from surface plasmon (quasielectrostatic) oscillations. In this article, we propose to realize subwavelength confinement in microwaves by using dipolarmode (quasimagnetostatic) magnon oscillations in ferrite particles. Our stu...

High permeability and high permittivity are hard to be achieved simultaneously, either in single-phased materials or in composite materials, such as ferrite-ferroelectric ceramic composites and ferrite-metal percolative composites. In this work, ultra-low percolation threshold is achieved in NiZnCu ferrite-Ag cofired ceramics, which endows the composite with both high permeability and high perm...

The effect of plastic deformation on the transformation of austenite to acicular ferrite in a Fe /Mn /Si /C alloy steel containing non-metallic inclusions was investigated. The transformation to acicular ferrite is retarded and the final fraction of acicular ferrite is reduced in plastically deformed austenite, which is a characteristic of a displacive transformation mechanism. The increase in ...

This book chapter is organized into four major parts. Firstly, it will cover an introduction of using spinel ferrite nanoparticles in biomedical applications, including the antibacterial properties. The second part will provide an overview of the structure and magnetism of spinel ferrites. The third part will focus on the preparation of cobalt ferrite and transition metal substituted cobalt fer...

The microstructural evolution of Fe–0.2C–5Mn steel during intercritical annealing with holding time for up to 144 hours was examined by TEM and STEM. It was demonstrated by TEM that the martensite lath structure gradually transformed into a lamellar ferrite and austenite duplex structure. The partitioning of manganese from ferrite to austenite was found by STEM. Typical Kurdjumov-Sachs orientat...

A small FMR ferrite disk strongly perturbs the cavity field. Graphical representation of the Poynting vector shows that due to the vortex structure the absorption cross-section of a ferrite particle can be much bigger than its geometrical cross-section. Spectral properties of magnetic oscillations in a ferrite disk show unique vortex structures for MS-wave functions.

The atomic level structure of a series of monodisperse single crystalline nanoparticles with a magnetic core of manganese ferrite was studied using X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES) techniques at both the Fe and Mn K-edges, and conventional and high resolution transmission electron microscopy (TEM and HRTEM). In particular, insights on the ...

calcium doped nickel ferrite powders have been prepared by sol-gel combustion technique. metal nitrates, such as calcium nitrate, nickel nitrate and ferric nitrate, were used as the source materials and citric acid and polyvinyl alcohol were used as the burning agent and agglomeration reducing agent, respectively. the average crystallite size of the prepared ferrite was in the order of ~70- 92 ...

The first evidence is provided for the existence of a tetragonal or slightly orthorhombic unit cell of bainitic ferrite. It supports the hypothesis that the excess carbon that persists in the ferrite, which is in contact with austenite, is a consequence of an increased solubility due to the change in symmetry from the conventional cubic unit cell. The deviations from the cubic cell are maintain...