Partial anhysteretic remanent magnetizations produced in rotating samples, and comparisons with corresponding rotational remanent magnetizations

Abstract

Summary. Characteristics of various types of partial anhysteretic remanent magnetization generated in samples rotating about a single axis, which was always parallel to the steady field, are investigated and compared with those of the corresponding rotational remanent magnetization, and where relevant, with those of gyroremanent magnetization. In contrast to results of previous studies using static anhysteretic remanences, the behaviours of these partial anhysteretic remanences generally resemble those of their rotational counterparts. One exception is that the production of rotational remanences is associated mainly with higher coercivities (20 or 30 mT and beyond), whereas particles with coercivities up to about 30 mT respond most strongly in certain cases to the anhysteretic induction process. Most of the observations generally may be accounted for in terms of the grain anisotropy of either single-domain particles (rotational remanences) or both single-domain and multi-domain particles (anhysteretic remanences). The maximum intensity of partial anhysteretic remanent magnetizations generated with the rotation axis inclined at various angles, 17, to the alternating field axis occurs when q is close to-n/3. Partial rotational remanent magnetizations produce a similar effect which is not fully consistent with conclusions drawn from a previous investigation on rotational remanent magnetization.