Ni-Zn Nanoferrites Synthesized by Microwave Energy: Influence of Exposure Time and Power

Abstract

This paper describes the synthesis of Ni-Zn nanoferrites by combustion reaction using microwave energy as a heating source, and evaluates the performance of these materials as absorbers of electromagnetic energy at frequencies between 4 - 12 GHz. The influence of the synthesis conditions on the structure, morphology and absorption characteristics was investigated. The powders were characterized by DRX, BET, AGM and reflectivity measurements in the frequency bands of 8 to 12 GHz. The XRD results show the formation of Ni-Zn ferrite phase and Fe2O3 and Ni as secondary phases. The crystallite sizes ranged from 32 to 42 nm. The parameters of exposure time and power of the microwave oven changed the final characteristics of the resulting powders. The morphology of all the powders consisted of soft nanoparticle agglomerates. The best saturation magnetization and attenuation results were 70 emu/g and -4.1 dB in the frequency of 10 GHZ.

HRTEM and FTIR investigation of nanosized zinc ferrite irradiated with 100MeV oxygen ions

“…The unique magnetic properties of ferrites with high resistivity make them applicable for high frequency applications [7,8]. Generally, these materials exhibit ferrimagnetic ordering but zinc ferrite exhibits antiferromagnetism having Néel temperature of about 10 K. The paramagnetic behaviour at room temperature changes to superparamagnetic when the particle size approaches to nanoregime and the corresponding change can also be seen in its structure which changes from normal to mixed spinel.…”

“…Generally, these materials exhibit ferrimagnetic ordering but zinc ferrite exhibits antiferromagnetism having Néel temperature of about 10 K. The paramagnetic behaviour at room temperature changes to superparamagnetic when the particle size approaches to nanoregime and the corresponding change can also be seen in its structure which changes from normal to mixed spinel. In ZnFe 2 O 4 , reduction of particle size from bulk to nanoregime, magnitude of magnetization depends on the thermal and mechanical treatment given during the synthesis or after the synthesis [1][2][3][4][5][6][7][8]. The thermal treatment is given by annealing or sintering and mechanical treatment is given by applying pressure.…”

Magnetic Evaluation of Ni-Zn Ferrites Doped with Aluminium

“…The combustion reaction synthesis has been effective in the preparation of single phase ferrites and in nanometric scale [11,12], and in addition the sintering or calcination has been used in ferrites prepared by combustion reaction with the aim to improve and to investigate the mechanism involved in the final product [13,14].…”

Ferrite Ni_0,5Zn_0,5Fe₂O₄ Synthesized by Combustion Reaction in a Microwave Oven Using Urea and Glycine as Fuel: Influence of Power

“…To obtain nanoparticles, and monophase samples of ferrite (when necessary) by this method, various synthesis conditions can be evaluated as an example, the form of external heating, and the type and quantity fuel [17]. One way of warming that has been widely used for the production of ceramic powders by combustion reaction is using microwave energy [18,19].…”