A coefficient determined by the magnetic circuit and the shape of the magnet. If the permeance coefficient is p, the magnet’s working point is the intersection of a straight line (the permeance line) drawn from the origin and having a slope of mOp and the B-H demagnetization curve. The permeance coefficient is used in designing magnetic circuits. For a stand-alone magnet, if the magnet is shaped long and fine in the magnetization direction, the permeance coefficient found setting H positive is larger.
Remanence is the magnetic induction or magnetic flux density that remains in a magnet after the magnet being fully magnetized and the external magnetic field being removed. It is represented by the y-intercept on a demagnetization curve.
the strength of the magnetic field that is needed to completely demagnetize a fully magnetized magnet. The higher the Coercivity (Hcj), the stronger the magnet’s resistance to the opposing field.
Also called normal coercivity, Hcb is the strength of the external magnetic field needed to reduce the magnetic induction to zero without irreversible demagnetization of the magnet.
(BH)max is a measurement for the maximum amount of magnetic energy stored in a permanent magnet. It is an indicator of magnetic strength.
A magnet is anisotropic if all of its magnetic domains are aligned in the same direction. This is achieved during the manufacturing process and ensures that the domains are 100% orientated in the same direction to deliver maximum magnetic output. This direction is called the ‘magnetic axis’.
The alignment is achieved by subjecting each magnet to a strong electromagnetic field at a critical point during the manufacturing process, which then ‘locks’ the domains parallel to the applied electromagnetic field.
An anisotropic magnet can only be magnetized in the direction (along its magnetic axis) set during manufacture, attempts to magnetize the magnet in any other direction will result in no magnetism. Anisotropic magnets are much stronger than isotropic magnets, which have randomly orientated magnetic domains producing much less magnetism. However, isotropic magnets are more flexible in terms of magnetization.