Faraday rotation and magneto-optical figure of merit for the magnetite magnetic fluids

L Kalandadze

doi:10.1051/epjconf/20111501028

Abstract

In the present paper, using magnetite magnetic fluids as examples, we consider the optical and magneto-optical properties of magnetic fluids based on particles of magnetic oxides, for the optical constants of the material of which, n and k , the relation 22 kn  holds. In this work the Faraday rotation is represented within the theoretical Maxwell-Garnett model. A theoretical analysis has shown that Faraday rotation for magnetic fluids is related to the Faraday rotation on the material of particles by the simple relation. According to this result in specific experimental conditions the values of the Faraday rotation prorate to q , which is the occupancy of the volume of the magnetic fluid with magnetic particles and spectral dependences of effect in magnetic fluid and in the proper bulk magnetic are similar. We also show that the values of the magneto-optical figure of merit for ultrafine medium and for the bulk material are equal.

Highlights

Magneto-optical research methods are successfully used to solve different types of task in the physics of magnetic phenomena
The magneto-optical properties of magnetic fluids are very different from the properties of the bulk ferromagnetic. This fact causes the changes in spectral and angular dependences of the magneto-optical effects. The reason for this is that magnetic fluids represent an example of a magnetic ultrafine medium composed with magnetic particles, the sizes of which are much less than the light wavelength
Our results are in a good relation with the experiments [5], where Faraday rotation has been studied in magnetite magnetic fluids with different concentrations

Summary

Introduction

Magneto-optical research methods are successfully used to solve different types of task in the physics of magnetic phenomena They are the powerful means to be used for the observation of domains and the boundaries of domains, as well as to examine the electronic energy of the structure of the solids [1]. The magneto-optical properties of magnetic fluids are very different from the properties of the bulk ferromagnetic This fact causes the changes in spectral and angular dependences of the magneto-optical effects. The reason for this is that magnetic fluids represent an example of a magnetic ultrafine medium composed with magnetic particles, the sizes of which are much less than the light wavelength. In some cases the fine magnetic particles could be used as a probe

Theory

Results and discussion

Conclusions