Features of the permeability spectra of CoZnW hexaferrites in the spin-reorientation phase transition region

Abstract—The hexaferrites of the Co2-xZnxW system have a number of outstanding properties among other hexaferrites. This makes them promising both for obtaining new physical data and for practical use. In this paper, we analyze the concentration and temperature dependences of the resonance frequencies of natural ferromagnetic resonance and the damping constant in the equation of motion of the magnetization vector of these materials in the vicinity of spin-reorientation phase transitions. It is shown that these hexaferrites can find practical application in the entire microwave frequency range

Computer simulation of processes of radiation-thermal heating

In this work we present results of computer simulation of radiation-thermal heating of magnetic materials to change their structure. The energy source is a pulsed electron accelerator. The simulation results are presented in the form of the temperature distribution in the irradiated material, depending on the pulse duration, pulse repetition rate and the parameters of the material

Synthesis of cubic ferrite CoFe2O4 by spray pyrolysis

The phase composition, morphology, and structural parameters of cobalt ferrospinel powders synthesized by spray pyrolysis combined with drop sol-gel combustion are determined. The obtained data are compared with those of the powders synthesized by sol-gel combustion

Magnetocrystalline anisotropy of the multiphase samples of the hexaferrites Ba2Ni2-xCuxFe12O22 studied by the ferromagnetic resonance method

This paper presents structural and magnetic investigation of the hexaferrites Ba2Ni2-xCuxFe12O22 system in the Cu2+ concentration range 0 ≤ x ≤ 1.4. Samples were synthesized according to traditional ceramic processing technology. The samples were multiphase, since the optimal conditions of synthesis were not specially worked out. According to the data of X-ray diffraction analysis, the samples contain both a target phase and impurity phases of magnetite and hematite, as well as hexagonal phase of Ba-M. The values of the saturation magnetization of the samples were a little more than the values in the literature. It could be explained by the contribution from impurity phases with large magnetization values. The values of the anisotropy fields of the separate phases, which are contained in the investigated samples, were determined by the method of ferromagnetic resonance. The anisotropy field decreases with an increase in the content of copper ion. It is show that the value of the anisotropy field of hexaferrite Ni2Y is close to the literature value

Effect of heat treatment on the structural parameters and magnetic properties of copper ferrite nanopowders obtained by the sol-gel combustion

Phase composition, structure parameters and basic magnetic characteristics obtained by the sol-gel combustion nanopowders of ferrospinel CuFe2O4 are investigated. A comparison of the properties of synthesized materials: first sample - immediately after the combustion of the gel and second sample - after annealing at 1073 K for 4 hours are performed. Annealing leads to an increase in the concentration of the phase with tetragonal crystal structure. Particle sizes and the value of anisotropy field of this phase also increased

Radiation-thermal synthesis of W-type hexaferrites

The results of investigations of the phase composition, structural parameters, static and dynamic magnetic properties of BaCo0.7Zn1.3Fe16O27 hexaferrites obtained by the method of self-propagation high-temperature synthesis in combination with mechanochemical activation and radiation-thermal post-sintering are presented. The prospects of the proposed energy-saving approach for the production of ferrite ceramics with a hexagonal structure is shown