  Zn doped Mn ferrites nanoparticles were fabricated by using Co-precipitation.
Variation in structure, magnetic and optical properties of MnZn ferrites has
been discussed. First of all, samples were synthesized, annealed at different
temperatures and then characterized. The as-synthesized and annealed samples
were investigated by X-ray diffraction (XRD), Scanning electron microscopy
(SEM), Energy Dispersive spectroscopy (EDX), Ultra Violet visible spectrometry
(Uv-Vis spectrometry) and Vibrating sample magnetometer (VSM). The average
crystallite size of MnZn ferrites nanoparticles determined from XRD were in the
range of 42 to 60 nm. These nanoparticles possess normal spinel structure. The
SEM images showed the physical shape of the samples, which showed that the as
prepared samples are more agglomerated and having flake like shape rather than
annealed at 700C while the samples have longitudinal or rod like shape on
annealing at 700C. The coercivity (Hc), saturation magnetization (Ms), and
remanence (Mr) of Nps were also calculated. The (Ms) value is increasing from
26 to 65 emu/g, the coercivity (Hc) is varying from 13 to 193 Oe and remanence
(Mr) has also showing increasing trend although very less, from 0.031 to 0.798
emu/g which are a little part of their bulk counter parts. The band gap energy
of the samples was showing decreasing trend as with the increase of particle
size which is of the order of 3.5 to 2.9 eV.
