Anhysteretic remanent magnetization in small steady fields

The phenomenon called anhysteretic remanent magnetization, ARM, has been known for a long time, but it has received relatively little attention. A knowledge of this type of magnetization is required in proper application of alternating field demagnetization techniques to rock magnetism problems. Over a wide range of low values of the steady field Hdc, the ARM intensity is a linear function of Hdc when the maximum alternating field intensity Hac is constant. The coercive force of the ARM is a function of Hac only, for small values of Hdc. Partial anhysteretic remanent magnetization, PARM, is analogous to partial thermoremanent magnetization, PTRM. It is shown that PARM's are additive in the same manner as PTRM's. These properties of ARM are useful in magnetic analyses to determine the magnetic nature of a material and to predict its behavior on exposure to a magnetic field.