Demagnetization

Demagnetization is a procedure or method used to eliminate unwanted (major or minor) magnetic fields. Demagnetization is also the reduction or elimination of magnetization. The demagnetization procedure can be performed as an automated process done in a VSM to remove residual magnetization resulting from substrate materials, magnetic artifacts, magnetic noise and exchange interactions and other sources. The Demag process results in a ‘baseline’ for differentiated ‘before and after’ Hysteresis loop measurements.

Alternative means to perform demagnetization are to heat the object above its Curie temperature, where thermal fluctuations have enough energy to overcome exchange interactions, sources of ferromagnetic order, and can disengage that order. In some applications and materials an electric coil with alternating current running through it, can also be used to generate alternating magnetic fields that oppose the magnetization.