Magnetic Susceptibility - Definition of Volume Susceptibility

Definition of Volume Susceptibility

See also Relative permeability.

The volume magnetic susceptibility, represented by the symbol (often simply, sometimes — magnetic, to distinguish from the electric susceptibility), is defined in the International System of Units — in other systems there may be additional constants—by the following relationship,

where

M is the magnetization of the material (the magnetic dipole moment per unit volume), measured in amperes per meter, and

H is the magnetic field strength, also measured in amperes per meter.

The magnetic induction B is related to H by the relationship

where μ₀ is the magnetic constant (see table of physical constants), and is the relative permeability of the material. Thus the volume magnetic susceptibility and the magnetic permeability are related by the following formula:

.

Sometimes an auxiliary quantity, called intensity of magnetization (also referred to as magnetic polarisation J) and measured in teslas, is defined as

.

This allows an alternative description of all magnetization phenomena in terms of the quantities I and B, as opposed to the commonly used M and H.