A study of some properties for Li-Mn nanoparticles ferrite using positron annihilation lifetime technique

Nanoparticle samples of the composition Li(0.5-0.5x)MnxFe(2.5-0.5x)O4, (x = 0, 0.25, 0.5 and 0.75) are prepared with a sol-gel auto combustion method. The nano grain size is decreased with increasing the manganese content. The analysis of PAL spectra indicated the existence of cluster defects. There are different correlations between the lifetime parameters with the manganese content. The relative intensity I2 and the trapping rate қ are increased for samples with x = 0.25 & 0.75, and are decreased for the sample with x = 0.5 relative to the pure nano Li-ferrite. The electrical resistivity takes the same behavior as the G.S. by increasing Mn content. The size of the domain walls is decreased with Mn content for mono-grain Li ferrite samples.