Hydrothermal Synthesis of Manganese Zinc Ferrites

Abstract

Hydrothermal synthesis has been used to synthesize nano‐sized manganese zinc ferrite powder. The results show that the pH value of the starting suspension has a decisive influence on the composition of the hydrothermally prepared manganese zinc ferrite powder. At a pH value of ∼8.5, stoichiometric amounts of manganese and zinc can be incorporated in the manganese zinc ferrite. The grain size of the powder increases with the temperature and time of hydrothermal treatment. The nanosized manganese zinc ferrite produced is superparamagnetic and becomes ferri‐magnetic after the ferrite grains become larger than ∼100 nm. The nanosized ferrite grains are very prone to oxidation and disintegrate at 600°C in air. The surfaces of the synthesized ferrite grains are covered with a thin film of water.