Ceramic materials in the system FeO-Fe3o4 have been produced by means of mechanical milling and sintering for application of their physical properties. Starting from powder mixtures of Fe and Fe3o4 or Fe and Fe2o4, as well as pure Fe3o4, a metastable solid solution of Fe and O has been produced. The amount of Fe dissolved varies according to the milling time and its initial content in the mixture. A protective Ar atmosphere is used in all stages of the milling process in order to avoid contamination. X-ray diffraction patterns show a clear displacement of the intensity maxima as a function of the milling time, suggesting the formation of a solid solution from the initial mixture. Use of Mossbauer spectroscopy reveals an increasingly higher amount of metastable wustite (Fe(1-X) as a function of milling time i.e., 500 h and 1000 h of milling produce 67 and 74 mol % Fe(1-X)O, respectively.