Magnetic susceptibility

Magnetic susceptibility is the ability of external magnetic fields to affect the nuclei of an atom. This may also be thought of as the “magnetisability” of a material, or the extent to which a material becomes magnetized when placed in an external magnetic field.

Magnetic susceptibility is related to the electron configurations of an atom. A nucleus surrounded by paired electrons is unaffected by external magnetic fields. A nucleus surrounded by unpaired electrons is affected by magnetic fields. Magnetic susceptibility will determine whether a material will be attracted to or repelled from a given magnetic field.

Magnetic materials may be classified as one of three types; diamagnetic, paramagnetic or ferromagnetic, depending of their susceptibilities. Diamagnetic materials will partly expel the external magnetic field, paramagnetic materials have small positive attraction and alignment with the magnetic field and ferromagnetic materials may have very strong attraction and alignment.