Magnetic properties of single-domain particles and the rock remanence

5. Conclusion

[47] The model of interacting single-domain particles underlying the analysis of relations between various types of magnetization is, in a certain aspect, similar to the model of an ideal gas in which every atom is represented, in a first approximation, by a particle that is only capable of energy and momentum exchange with other particles. It is remarkable that, even in terms of this simple model, one can obtain the Mendeleev-Clapeyron equation, having a rather wide application area. A simple technique incorporating a finite volume of atoms and their possible interaction yields the Van der Waals equation predicting vapor-liquid transitions. Of course, a more realistic description of an atom as a complex quantum-mechanical system appears to be preferable, but numerical problems involved in this approach are evident; it is also evident that some reasonable restrictions are inevitable in incorporating properties of the atom, which is a main constituent of the kinetic theory of gases. A similar situation is observed in the case of the system of interacting single-domain particles whose properties are fairly complex, as is evident from the results of this paper. Therefore, it is natural to accept, as a first approximation, the simplest model of a single-domain particle and introduce additional restraints only if model results diverge significantly with experimental data. In our opinion, the results that we obtained from this detailed study of properties of single-domain particles can be useful for gaining insights into such well-known phenomena as the stabilization of the magnetic moment with time, the metastability of magnetic states in rocks, the pressure-induced destruction of remanent magnetization, and so on; these phenomena cannot be interpreted in terms of the simplest assumptions on the properties of I_r, H₀ and the interaction field H.