Structural and magnetic properties of ZnxCul.4−xMn0.4Fel.2O4 ferrites

Compositions having the general formula ZnxCul.4−xMn0.4 with x = 0.0 to 0.5 have been prepared using the standard ceramic technique. The structural and magnetic properties are investigated by means of X-ray diffraction, magnetization and a.c. susceptibility measurements. The lattice constants are determined and the applicability of Vegard's law has been tested. The X-ray diffraction data showed that the unit cell parameter increases with the Zn content x. The variation of the saturation magnetic moment per formula unit measured at 300 K with the Zn content x is satisfactorily explained on the basis of Neel's collinear spin ordering model for x = 0.0 to 0.2. For x > 0.2, the observation indicates the existence of a Yafet–Kittel type of magnetic ordering in the system. The Curie temperature obtained from a.c. susceptibility measurements decreases linearly with the increase of the Zn content x from x = 0.1 to 0.5.