Demagnetizing energy

In the case of Co—Cr having perpendicular anisotropy there is, in principle, a competition between the uniaxial anisotropy of a hexagonal stmcture and the demagnetizing energy of the thin film. In the case of magnetically separated Co—Cr columns (particulate morphology) then also the shape anisotropy contributes to the perpendicular anisotropy. 

Rhodes P, Rowlands G (1954) Demagnetizing energies of uniformly magnetized rectangular blocks. Proc Leeds Philos Literary Soc Scientific Section 6 191-210... 

Figure A2.1.11. Magnetic cooling isothemial magnetization at 4 K followed by adiabatic demagnetization to 0.04 K. (Constructed for a hypothetical magnetic substance with two magnetic states with an energy...

Figure 20.1. The magnetization process (a) demagnetized state (b) unsaturated state (c) saturated state. When an external magnetic field is applied, domain rotation and domain wall motion occur simultaneously or sequentially. Domain configuration can be found by minimizing the total energy related to magnetization. (From Ref 1, with permission from Elsevier.)...

If the field is removed, there is a residual magnetization or remanence, Br. A reverse field, //, (coercive force), is required to demagnetize the material. The area enclosed by the B-H curve (hysteresis) is the energy loss per cycle, and the... 

The operating state of a permanent magnet lies in the second quadrant of a B-H hysteresis loop since the magnet is always subject to its own demagnetizing field. Apart from its coercivity and remanence, a permanent magnet material is rated by its maximum energy product ... 

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