Effect of ball milling on defects level, Curie point and microstructure of LiTiZn ferrite ceramics

In a present work, a comparative study of two types of LiTiZn samples of ferrite ceramics, which were sintered using conventional ceramic technology at a temperature of 1010 °C for 2 h and which were made with preliminary mechanical treatment in a ball planetary mill, was carried out. It is shown that mechanical treatment in a ball mill leads to a decrease in the defects level, an increase in the Curie point and a demagnetizing factor of ferrite ceramics. The growth of the demagnetizing factor is associated with an increase in the porosity of ferrite ceramics samples pre-grinded in ball. According to the X-ray phase analysis data, the lattice parameter and the coherent scattering region decrease in this case, and the microstrain is reduced by an order of magnitude. The defects level was assessed by the results of mathematical processing of the temperature dependences of the initial permeability using the previously proposed phenomenological expression. Measuring TG/DTG curves in a magnetic field allowed, on the one hand, to confirm a significant difference in Curie points for different types of samples, on the other hand, to detect the presence of an additional magnetic phase in ball-milled ferrite ceramics samples.