Effect of rare earth substitutions on some physical properties of Mn-Zn ferrite studied by positron annihilation lifetime spectroscopy

Mn-Zn ferrite substituted with rare earth ions have been investigated by means of positron annihilation lifetime spectroscopy (PALS). The variations of lifetime parameters τav, I2, and κ with ionic radius of rare earth ions, grain size and electrical resistivity for all samples have been studied. The intergranular pores increase with increasing the ionic radius of rare earth ions and grain size of the samples.