FERRIMAGNETIC ZINC FERRITE FINE POWDERS

Partially inverted fine powders of zinc ferrite (ZnFe2O4) were produce d by chemical aerogel synthesis. These powders showed magnetic orderin g at temperatures to 250K. Upon ball milling, a much higher inversion parameter was attained,yielding ferrimagnetic powders having small rem anence and coercive fields at room temperature. Due to the small mean particle size, superparamagnetic behavior was seen at temperatures abo ve 25K. Powder properties were characterized by x-ray diffraction, ele ctron microscopy, calorimetry, magnetometry, and Mossbauer effect spec troscopy techniques.