magnetisation magnetization process of becoming or making sth magnetic They should understand how the Weiss field leads to the occurrence of spontaneous magnetisation . Saturation - The point at which the tape is fully magnetized and will accept no more magnetization . Global models take no account of magnetic fields caused by the magnetisation of local rocks ( the crustal anomaly field ) , nor of the regular daily variations in the global field , nor of disturbances in the field . state of being magnetised Coercivity : The reverse field that must be applied to a magnetised sample to reduce its overall magnetisation to zero . The electron magnetisation can then be detected directly via a tuned RF coil whose axis is oriented along the direction of the applied field . In particular they measured the magnetization of an ensemble of 107 copper rings , each only 0.5 microns in diameter .