In the literature there are data on structural, optical and magnetic properties of cubic solid solutions in the NiO-ZnO , MgO-ZnO and MnO-ZnO systems, while solid solutions of the FeO-ZnO system remain poorly studied. The latter system is of particular interest because in the series of 3d metal monoxides "FeO" (wüstite) has the largest magnetic anisotropy constant , the widest region of oxygen non-stoichiometry, which accounts for its high specific electrical conductivity of the hole type (p-type) . In contrast, zinc oxide (w-ZnO) remains a widegap n-type semiconductor even after treatment at high temperatures and pressures .