The first part of this chapter deals with the magnetic materials under static field conditions and their properties. In this part, a detailed description is given for the interaction between a magnetic material and magnetostatic field and how the magnetization process takes place when the material is immersed in the field. The concepts of magnetic susceptibility, permeability, and relative permeability, which are related to the magnetization process, are discussed. Further topics that are related to magnetostatic such as magnetostatic energy, boundary conditions for magnetostatic fields, inductance, and the magnetic circuit are also discussed in this part. The second part of the chapter discusses the dispersive materials and introduces metamaterials and their classifications. Using mathematical analysis it is shown that under a static fields conditions materials are characterized by a constant permittivity and permeability, while under time-harmonic fields the induced polarization and magnetization may result in a permittivity and permeability that are frequency-dependent. Different material models that describe the behavior of the permittivity and permeability with frequency in addition to the classification of metamaterial are presented. The topics of the chapter are supported by numerous illustrative examples, figures, and solved problems in addition to homework problems at the end of the chapter.
Keywords: Artificial magnetic conductors Debye model dispersion Drude model hysteresis loop inductance magnetic anisotropy magnetic circuit magnetic hysteresis magnetic materials magnetic susceptibility magnetization magnetostatic energymetamaterialspermeabilityrelative permeability.