Motion of Domain Walls and Hysteresis Loops

When the field is removed, there is a resistance to domain wall motion preventing reorientation of the domains. As a result there is a residual magnetization, known as remanence B, and the material acts as a permanent magnet. 

FIGURE 33.22 The variation of S as H alternates. The insets illustrate the domain structure at various points along the hysteresis cun/e. 

Spinel (cubic ferrites) 1 MeOtlFsaOs MeO = transition metal oxide, e.g., Ni,Co, Mn, Zn Soft magnets 

Garnet (rare earth ferrites) 3 M 203.5F 203 MegOs = rare earth metal oxide, e.g., Y2O3, GdsOs Microwave devices 

Magnetoplumbite (hexagonal ferrites) 1 Me0 6Fe203 MeO = divalent metal oxide from group IIA e.g., BaO, CaO, SrO Hard magnets 

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