POLYCRYSTALLINE Ni, Zn AND Ni-Zn FERRITE TARGETS FOR PLASMA LASER DEPOSITION TECHNIQUE

[[abstract]]Ni, Zn and Ni-Zn ferrites targets to by used in pulsed laser deposition of thin ferrite films were prepared by a conventional ceramic technique. The properties of the ferrites were evaluated from XRD, SEM and EDX data. The electrical and magnetical characteristics of the investigated specimens are interpreted in terms of the role played by the sintering condition on the microstructure and on stoichiometry

POLYCRYSTALLINE Ni, Zn AND Ni-Zn FERRITE TARGETS FOR PLASMA LASER DEPOSITION TECHNIQUE

[[abstract]]Ni, Zn and Ni-Zn ferrites targets to by used in pulsed laser deposition of thin ferrite films were prepared by a conventional ceramic technique. The properties of the ferrites were evaluated from XRD, SEM and EDX data. The electrical and magnetical characteristics of the investigated specimens are interpreted in terms of the role played by the sintering condition on the microstructure and on stoichiometry

Jiles-Atherton Magnetic Hysteresis Parameters Identification

This paper presents a method of fitting the magnetic hysteresis curves using a calculating algorithm within a computer programme. The calculating programme uses the equations of the Jiles-Atherton model to simulate the M(H) magnetization curve. The aim of this program is to find the values of the parameters which are part of the Jiles-Atherton model once the regression curve for a major magnetization curve obtained experimentally is found. The values of these parameters can be increased or decreased gradually. The parameters modification takes place in such a way that the root mean square deviation between the points of the two graphs, also experimentally simulated, should decrease gradually and, in the end, it should be found below the preestablished percentage value in comparison to the previous value. The procedure for minimizing the root mean square deviation has as a result the fact that the simulated curve represents the regression curve. The calculating programme considers a second method of calculating the values of the parameters by using the already found regression curve. This paper also presents the values of the Jiles-Atherton model parameters obtained by fitting the magnetization curves of several cobalt ferrites samples, sintered at different temperatures

Models of Hysteresis in Magnetic Cores

A new method of obtaining physical information about a system of fine ferrite powder, from the hysteresis experienced by a ferromagnetic core as it dissipates energy in an RLC circuit is presented. The models of the magnetization processes are classified in three categories : physical, phenomenological and mixed. Hodgdon developed a purely mathematical model that was tested on magnetization processes in magnetic cores. The values of the model's parameters are calculated from experimental data obtained in a series RLC circuit. The capacitor discharges through the circuit and the core performs a complex magnetization process. The voltage across the capacitor and the current intensity are measured. These magnetization processes could be also simulated with a mixed-type model. The identification methodology of the mixed model requires the measurement of some magnetization curves : the first magnetization curve, the major hysteresis loop, the isothermal remanent magnetization process and the d.c. demagnetization process. In order to preserve the simplicity of the experimental data measurement and to perform the identification of the mixed model, some of the experimental curves required by the identification methodology were simulated with the Hodgdon model. Experiments were performed on soft MnZn ferrite core. The results of the identification are discussed

COMPLEX PERMEABILITY AND POWER LOSS MEASUREMENTS ON Ni-Zn-In-Ti FERRITES

Polycrystalline high saturation magnetization nickel-zinc ferrites with fixed quantity of indium and varied quantities of titanium and zinc with the general formula Ni0.65Zn0.35+xIn0.01TixFe1.99-2x O4, where x varies from 0.00 to 0.25 in steps of 0.05, have been prepared by conventional ceramic technique to examine their usefulness for high frequency power applications. Sintering of the samples was carried out at 1250 °C for 4 hours in air atmosphere followed by natural cooling. X-ray diffraction patterns confirm single phase spinel structure in all the samples. Complex permeability measurements exhibit a stable frequency response up to 5 MHz beyond which the real permeability drops and imaginary permeability increases to display a peak around 10 MHz. Power loss density has been observed to be very low up to 3 MHz, however, it increases rapidly beyond 3 MHz; thus it is suggested that these materials could be useful as core materials up to 3 MHz. The results are analysed and discussed in terms of the changes in compositions, microstructure and the associated processes of resonance and relaxation due to domain wall movements and damping of spin rotations contributing to the variations in permeability and losses

Effect of slow charged 90 keV Ne 8+ ions on zinc ferrite nanoparticles

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