“…There are two contributions to the uniaxial anisotropy: one that comes from the CoNbZr matrix, and another from the Tb ions. According to the mechanism proposed by Calleja et al [12], the induced uniaxial anisotropy has its origin mostly in the part of the local anisotropy that comes from the single-ion anisotropy of the Tb sites via spin-orbit coupling. When this is the case, H k depends linearly on the Tb content.…”