Magnetic susceptibility

In electrical engineering, the magnetic susceptibility is the degree of magnetization of a material in response to a magnetic field. The dimensionless volume magnetic susceptibility is represented by the symbol χ.

where M is the magnetization of the material (the magnetic dipole moment per unit volume) and H is the magnetic field strength.

If χ is positive the material is called paramagnetic, and the magnetic field is strengthened by the presence of the material. If χ is negative then the material is diamagnetic and the magnetic field is weakened in the presence of the material.

The magnetic susceptibility and the magnetic permeability (μ) are related by the following formula:

where is the permeability of vacuum (see table of physical constants).