Effect of La~(3+) Substitution on the Structural and Magnetic Properties of Mn-Zn Ferrite Prepared by Sol-Gel Auto-Combustion Method

摘要

Spinel ferrite with the chemical formula of Mn_(0.5)Zn_(0.5)LaxFe_(2-x)O_4 (x= 0.02,0.04,0.06,0.08, 0.10) were prepared by a sol-gel auto-combustion method. The effect of the rare-earth substitution on the microstructural properties of the synthesized powders were investigated through X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM), while for the magnetic properties, vibrating sample magnetometer (VSM) measurements were made. XRD patterns revealed characteristic peaks corresponding to spinel Mn-Zn ferrite structures with accompanying secondary phases, such as Fe203 and LaFe03. The initial addition of La~(3+) into the spinel ferrite system resulted in an initial spike of the lattice parameter and crystallite size before proceeding to decrease as the rare-earth content continues to decrease. FESEM micrographs reveals agglomerated particles with considerable grain size distribution. The magnetic properties, especially the saturation magnetization, M_s, was found to decrease with each increase in La~(3+) substitution. The research findings revealed the critical influence of the La~(3+) substitution towards the overall structural and magnetic properties of the Mn-Zn ferrite samples.