Study of cation distribution and macro-magnetic properties of magnesium and aluminum co-substituted lithium ferrite

摘要

The structural and bulk magnetic properties of mixed spinel ferrite system Mg_xAl_(2x)Li_(2.5(1-x))O_4 (x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5) have been investigated by means of X-ray diffraction, magnetization and a.c. susceptibility measurements. The cation distribution determined through X-ray data are supported by the magnetization and susceptibility measurements. The study has revealed the strong octahedral site preference of Li~+ and A1~(3+) as compared to Mg~(2+). It is also found that the magnetic ordering in the system is of collinear type and the variation of magnetization can be explained on the basis of Neel's collinear spin model. The Ned temperatures calculated theoretically are in good agreement to those deduced experimentally.