Defects and magnetic studies of nanocrystalline cobalt substituted manganese ferrite probed by positron annihilation lifetime spectroscopy and magnetic measurement.

Cobalt substituted manganese ferrite nanoparticles, MnCoFeO (x = 0.0, 0.1, 0.

Positron annihilation and magnetic studies of gamma irradiated nickel ferrite nanoparticles sintered at various temperature.

The effects of gamma irradiation on structure and magnetic properties of nickel ferrite nanoparticles, prepared by the sol-gel method and sintered at 300, 500 and 900 °C, are studied through X-ray diffraction, positron annihilation lifetime spectroscopy, coincidence Doppler broadening spectroscopy and vibrating sample magnetometer. The prepared samples were irradiated with gamma rays from Co, Cs and Na for 1, 2 and 3 weeks that received 0.47, 0.