MAGNETISM IN METALS AND ALLOYS

That is, among the pure iron forms, only ferrite (a, bcc) is magnetic. This is intriguing, as the 5-Fe form also exhibits a body-centered cubic crystal structure. This must indicate that in addition to the simple 3D arrangement of lattice iron atoms, their individual magnetic dipoles must also be suitably aligned in order to yield a particular magnetic behavior. 

In contrast to diamagnetism, where all valence electrons of each atom are spin paired, paramagnetism is found in solids where the constituent atoms contain an unpaired valence electron(s). In a simple paramagnetic substance, the unpaired electrons spins are randomly oriented within the solid. Upon exposure to an external magnetic field, the spins become collectively oriented in a parallel direction to the applied field. However, the dipoles re-randomize when the field is removed. 

In a ferromagnetic material, the magnetic dipoles generated from unpaired electrons tend to align in the same direction, even in the absence of an external magnetic 

The larger the gap between Bq and 5r, the more effective the material will be for magnetic storage applications. Magnetically soft materials such as pure iron, low 

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