Mössbauer studies of nanosize Mn1−xZnxFe2O4

Nanosized mixed ferrite Mn1−xZnxFe2O4 (x=0.0, 0.35, 0.5, 0.65, 1) has been prepared by hydrothermal route at pH 9 and 210°C and studied by X-ray diffraction, magnetization measurement and Mossbauer spectroscopy. The size of the particles decreases gradually as the zinc concentration is increased. The cation distribution has been found to strongly depend on the process parameters. On annealing the system the cation distribution changes from a metastable state to a stable state which enhances the superparamagnetism. ZnFe2O4 with average particle size of 4 nm shows magnetic ordering even at room temperature.