Chromium doped gamma ferrite nanopowders (16.91 nm to 25.61 nm) of the
composition (Fe2-xCrxO3 for x = 0.00, 0.05, 0.06, 0.07, 0.08,
0.09, 0.10) were successfully synthesized by a modified solution combustion
method using citric acid as fuel at a temperature as low as 150 °C. The
so prepared samples were examined by powder XRD for phase identification and
crystallite size determination. The dimensions of particle size as
calculated from XRD are in good agreement with those evaluated by
transmission electron microscope (TEM). Fourier Transform Infrared (FTIR)
analysis was carried out to identify the various chemical bonds present in
the system. Magnetic examinations were performed in terms of magnetic
susceptibility and hysteresis plots. A decrease in the blocking temperature
with the increase of dopant concentration was observed which is explained on
the basis of Néel's relaxation theory. A simple model has been suggested
to explain the behaviour of hysteresis trends as the function of dopant
concentration.