2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/98123We calculate the anisotropy energy of a single-domain ferromagnetic particle in which the only source of anisotropy is the presence of non-magnetic impurities. We find that such anisotropy takes the form of combined easy-axis and easy-plane anisotropies, with random orientations of the axes. Typically the anisotropy energy is of order $N^{1/2} \hbar/tau_{so}$, where $N$ is the number of electrons in the ferromagnetic particle and $τ_{so}$ is the spin-orbit time.4 Pages, 1 figureMesoscale and Nanoscale Physicstext