Self-reversal of the magnetization of natural and synthesized ferrimagnets

According to modern concepts, the reverse magnetization of rocks is a result of polarity reversals of the terrestrial magnetic field. However, rocks sometimes become magnetized antiparallel to an applied field during laboratory experimentation. This phenomenon is called self-reversal of magnetization. Self-reversal is also observed when magnetizing synthesized ferrimagnets. This poses the challenge of determining the true nature of the reverse magnetization of rocks. Discussed in this review devoted to investigations into self-reversal of rock magnetization, with emphasis on the physical mechanisms of self-reversal, are both the experimental and theoretical studies of the authors, including results obtained in terms of the model they developed based on the Neel N type self-reversal mechanism. A comparison of computer simulations with experimental results is also presented. (reviews of topical problems)