Analytical prediction of the magnetization curve and the ferromagnetic hysteresis loop

We have obtained theoretical expressions for the ferromagnetic magnetization curve and hysteresis loop using an extension of the general ideas of the Globus model for polycrystalline ferrimagnets. In this work we take into account the force which results from the variation of the total energy (magnetic energy plus surface energy) in order to find the value of the critical field. Our theoretical magnetization curve agrees well with the experimental curve and our hysteresis loop has the general qualitative features of the corresponding experimental loops.