PHYSICAL AND MAGNETIC PROPERTIES OF NANOSIZED MN0.5NI0.5¬FE2-XPRXO4 PREPARED BY CO-PRECIPITATION METHOD

Nanosized Mn0.5Ni0.5Fe2-xPrxO4, x=0.0, 0.02, 0.04, 0.06, 0.08, 0.1 and 0.15 are prepared by co-precipitation method at calcination temperature 650oC for 4 hours. X-ray diffraction patterns show the presence of the cubic (Mn-Ni)- ferrite phase and anti-ferromagnetic a-Fe2O3. The variation in the lattice parameter “a” is due to the replacement of smaller radius ions Fe+3 by larger radius ions Pr+3. Transmission electron micrographs indicate that the particles are spherical in shape. The moderately agglomerated particles are present due to the interaction between the magnetic nanoparticles. UV-visible optical (UV) and Fourier Transform Infrared (FTIR) spectroscopies show a significant change in the absorption bands as the Pr content increases. The calculated values of the optical band gap energies show an increase as the Pr content increases. This is due to the decrease of the particle size. From VSM analysis, it was found that the saturation magnetization (Ms) and the coercivity (Hc) are strongly dependent on Pr content. The results of M-H loop are interpreted in terms of the observed anti-ferromagnetic phase a-Fe2O3, phase core shell interaction and cation redistribution