Magneto-crystalline cluster structure of the lithium-titanium ferrite studied by polarized neutrons

Magnetic structure of the Li-Ti-Zn ferrite when is annealed and slowly cooled down exhibits presence of magnetic clusters which arise due to the thermal diffusion of the Li, Fe and Ti ions. The same materials annealed over 1300 K and cooled down fast no clusters. The polycrystalline sample of chemical formula Li0.673Zn00.3Mn0.05Ti0.695Fe1.282O4 was studied by the polarized neutron diffraction and low-angle scattering method. The cation distributions are determined for the sample with and without cluster structure. The mean clusters diameter and their magnetic moment are evaluated as D=(6.6±0.1) nm and Mc=(880±120) BM, respectively. Basing on the neutron diffraction reflections (220) and (400) the magnetization process is studied for both samples. Analysis of the cluster structure magnetization was carried out using a modified Langevin function containing the magnetic intercluster interaction. The value of the cluster magnetic moment determined in this way by the fitting procedure is equal Mc=(800±10) BM. author. 8 refs, 4 figs, 2 tabs