The physical and chemical properties of some nickel-zinc ferrite compounds

The work reported forms part of a general investigation aimed at elucidating the mechanisms giving rise to magnetic and dielectric losses in ferrites. For this purpose the nickel-zinc ferrite system was chosen as a simple system containing materials whose properties fall within a convenient range for measurement. In particular, the paper describes the preparation and some properties of a series of nickel-zinc ferrites in which the iron content has been made less than the stoichiometric value. The primary aim in preparing these materials was to find to what extent the resistivity at microwave frequencies could be increased in such iron-deficient preparations. Although an increase of the resistivity at 9.6 Gc/s from about 50 ohm-cm to 500 ohm-cm is obtained, this alone would not be adequate for practical materials. Other properties of the materials have been measured and their variation with iron content explained.