Microstructure and permeability studies of mixed Li-Cd ferrites

Some microstructure-related properties of Li 0.5− x/2 Cd x Fe 2.5− x/2 O 4 ferrites have been reported. SEM micrographs show an interesting grain growth mechanism. Grain size increases up to x=0.3 and then decreases very slowly beyond it. Saturation magnetisation also follows the same trend. But initial permeability shows continuous increase up to x=0.6 and is explained on the basis of non-magnetic grain-boundary model. The variation of initial permeability and AC susceptibility with temperature shows normal ferrimagnetic behaviour. The Curie temperature decreases continuously with x, which is attributed to the decrease in the strength of the A–B interaction.