Embodiments disclosed herein relate to using
cobalt (Co) to fine tune the magnetic properties, such as permeability and magnetic loss, of
nickel-
zinc ferrites to improve the material performance in electronic applications. The method comprises replacing
nickel (Ni) with sufficient Co+2 such that the relaxation peak associated with the Co+2 substitution and the relaxation peak associated with the
nickel to
zinc (Ni / Zn) ratio are into near
coincidence. When the relaxation peaks overlap, the material permeability can be substantially maximized and magnetic loss substantially minimized. The resulting materials are useful and provide superior performance particularly for devices operating at the 13.56 MHz
ISM band.