The variation of the transition phenomena in the spinel structure; of
Li_1-x Ti_x Lay Fe_2-y O₄ ferrite from the ferrimagnetic to paramagnetic state was
observed by substituting Ti for Li in compound. XRD analysis was carried out
in order to find a correlation between the average lattice parameter, crystal size
on Ti content. Drastic change was observed between x=0.5 and x=0.7 in the
magnetic measurements which agrees well with the percolation theory. The
magnetization as calculated from susceptibility measurements as a function of
temperature and magnetic fields was interpreted in view of Ti contents. The
measurements showed that the magnetization increases with increasing
magnetic field which is a normal trend of ferrites in the ferrimagnetic region.
The susceptibility decreases as the temperature increases due to the increase of
the lattice vibration as well as the spin disorder. In addition, the existence of
small quantity of La ions influences the magnetic properties of such materials.
The hysteresis loops of the investigated samples showed that by increasing Ti
and decreasing Li contents the magnetic parameters Ms and Mr decrease as Hc
increases. The calculated effective magnetic moment μeff also varied with Ti
content, taking into consideration the screening effect of both Ti, Li and La³⁺
ion.