Gyromagnetic Properties of Ferrites

This chapter explains gyromagnetic phenomena in microwave ferrites near their ferromagnetic resonance. Gyromagnetic phenomena are associated with magnetization motion of the spin magnetic moment of electrons in the magnetic atoms of ferrites. The chapter describes various techniques to measure magnetic and dielectric spectra of ferrites as gyromagnetic media are overviewed. The examples of the typical measures microwave magnetic spectra of spinel, garnet, and hexagonal ferrites are given. The chapter further provides an overview of some electrodynamic problems of wave propagation in extended ferrite media and interaction of electromagnetic waves with localized ferrite samples. A special attention is paid to small perturbation technique, widely used to analyze waveguides, transmission lines, and cavities containing ferrite samples with at least one dimension, which allows for magnetostatic approximation. The chapter further presents a gyromodel based on gyrovector formalism developed by a Russian physicist L. K. Mikhailovsky (1928‐2014).