Studying the influence of supply pulse duration on the phase composition of iron oxides obtained by the plasma-dynamic method

I I Shanenkov,A S Ivashutenko,A A Sivkov,Y L Shanenkova,M I Gukov

doi:10.1088/1757-899x/1019/1/012096

Abstract

Magnetic materials and in particular iron oxides are of a great practical interest. The magnetite phase and the unique epsilon phase of iron oxide can be especially pointed out. The main difficulty in the synthesis of the epsilon phase is connected with the fact that it can exist only in a nanoscale state and is extremely difficult to obtain. We used the method of direct plasma dynamic synthesis, which allows obtaining multiphase powders of iron oxides containing both the epsilon phase and magnetite. It was found that by varying the initial parameters of the power system, namely the pulse duration by increasing the capacitance of the capacitive energy storage, it is possible to influence the phase composition of the obtained products and to achieve the preferential output of the epsilon phase. In addition, in the mode with the maximum pulse duration, when the best product is obtained from the point of the epsilon phase output, the system efficiency of converting the stored energy into released energy significantly increases. In general, it has been established that such a regime is most favorable for the system operation for the purpose of the iron oxides synthesis.

Highlights

Magnetic materials are the most popular and used in various fields of science and technology
The aim of this work was to estimate the influence of the supply pulse duration on the phase composition of the iron oxides synthesized by plasma dynamic method
In order to study the influence of the supply pulse duration tpul on the phase composition of the plasma dynamic synthesis products, a series of experiments were carried out with the varied capacitance value from 7.2 mF to 28.8 mF

Summary

Introduction

Magnetic materials are the most popular and used in various fields of science and technology. There are 7 non-hydrated phases of iron oxides with different structure and physical properties: α-Fe2O3 (hematite), β-Fe2O3, γ-Fe2O3 (maghemite), ε-Fe2O3, z-Fe2O3, FeO and Fe3O4 [2]. All of them have their own features, but the ε-Fe2O3 and Fe3O4 phases are of the greatest practical interest, due to their unique magnetic properties. Particles of the magnetite phase have a maximum saturation magnetization (92 G·cm3/g) among ferrites at room temperature [1]. These properties can be useful for creating on their basis modern permanent magnets used for storing information and other electronics. Despite a number of known method for magnetite synthesis, obtaining the epsilon phase is a rather difficult scientific task, due to the fact that it can exist only in a nanoscale state, as well as it is thermodynamically unstable [3, 6]

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