Microwave Faraday Rotation Research Articles

Faraday Effect for Localized Electrons in Insulators

The formulation of the Faraday rotation in terms of dielectric constants is extended for localized electrons in insulators to include the contribution from the magnetic dipole (MD) transition in addition to the electric dipole (ED) transition. The rotation comprises four different types of terms, each of which is separated into “diamagnetic” and “paramagnetic” terms. Two of the four terms consist of absorption-type curves, and they are absent when only ED or MD transition is considered. These new terms may be important to identify the presence of the MD transition. The ω 2 -dependence of the rotation at ω→0 is always proven even though a special consideration is required for the case where the ground state is a Kramers doublet. Two applications are presented; the optical Faraday rotation for rare earth compounds with C 3 h local symmetry; the microwave Faraday rotation for a low-lying Kramers doublet. Some typical curves of the dispersion of the rotation are given. The microwave Faraday rotation may be an...

Microwave Faraday Rotation in Ferrite Powders

Microwave Faraday Rotation in Ferrite Powders

Measurement ofF-Center Concentration and Relaxation Time by Microwave Faraday Rotation

The use of a bimodal cavity for the observation of electron spin resonance is described. The two samples of NaCl containing $F$ centers used by Blumberg are investigated by electron spin resonance. Their $F$-center concentrations are found to be 4.4\ifmmode\times\else\texttimes\fi{}${10}^{17}$ and 2.3\ifmmode\times\else\texttimes\fi{}${10}^{18}$ electrons/${\mathrm{cm}}^{3}$, respectively. The spin-lattice relaxation time at room temperature of the $F$-center electrons is found to be 1.7 microseconds.

On Some Problems in Designing Microwave Faraday-Rotation Devices (Correspondence)

During recent years a substantial effort has been made to obtain special ferrites for microwave applications. The authors opinion is that in many cases this effort was not supported by real necessity and that many existing commercial materials may reveal surprising microwave properties after a persistent and careful preparation of working conditions.

Microwave Faraday Rotation in Antiferromagnetic MnF2

Microwave Faraday rotation was observed in MnF/sub 2/ from 30 to 300 deg K. The antiferromagnetic resonance frequency is computed from the rotation measurements below the Neel point. The results are in good agreement with direct observation of the antiferromagnetic resonance and molecular field theory extrapolations except close to the transition where evidence for magnetic clustering is found. The Kramers-Kronig relations are applied to antiferromagnetic media and it is shown that the Faraday rotation depends both on the shift of the resonance with field and on very small field-induced intensity changes which are present. A study of Faraday ellipticity establishes the need for using terms in the equation of motion which relax the magnetization toward the instantaneous field direction (auth)

Microwave Faraday rotation: Measurement of the conductivity tensor

Microwave Faraday rotation: Measurement of the conductivity tensor

Microwave Faraday Rotation: Design and Analysis of a Bimodal Cavity

The design and analysis of a bimodal cavity for the observation of microwave Faraday rotation is presented. An equivalent circuit of lumped elements is developed and the coupling between degenerate cavity modes is expressed in terms of the elements of the susceptibility tensor of the material producing the rotation. The theory is checked against experimental results with a paramagnetic salt and substantial agreement is obtained. A cavity of this type when used in conjunction with superheterodyne detection appears to provide a high sensitivity spectrometer for the observation of magnetic resonance.

A Method for Measuring Small Angles of Microwave Faraday Rotation

A Method for Measuring Small Angles of Microwave Faraday Rotation

Performance of Ferrites in the Microwave Range (Abstract)

The discovery of microwave Faraday rotation in ferrites has opened up a whole new field of investigation and applications. An elementary explanation of the cause of Faraday rotation will be given with the aid of a model of a spinning electron, which can demonstrate ferromagnetic resonance and negative permeability. Some of the applications of ferrites to microwave circulators, modulators end phase changers will be discussed.

Microwave Faraday Rotation in Liquid Oxygen

Microwave Faraday Rotation in Liquid Oxygen