The effect of molar ratio on structural and magnetic properties of BaFe۱۲O۱۹ nanoparticles prepared by sol-gel auto-combustion method

Nanocrystalline particles of barium hexaferrite has been prepared by the sol–gel auto- combustion method using iron and barium nitrate with a Ba:Fe molar ratio of ۱:۱۰. The effect of fuel such as citric acid and aspartic acid was investigated on the structure and magnetic properties of nanoparticles. The results revealed that the formation of barium hexaferritefine particles is influenced by molar ratio of metal nitrates to fuel. The formation of pure crystallized BaFe۱۲O۱۹ nanoparticles occurred when the precursor was heat-treated at ۹۰۰°C for ۲ h. Nanoparticles of barium hexaferrite with average crystalline size between   ۶۰-۶۹ nm has been obtained. X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) were employed to identify the structural phases, surface morphology and magnetic properties of the prepared nanoparticles, respectively.  Magnetic measurements showed that the BaFe۱۲O۱۹ nanoparticles exhibited a great coercive field and high saturation magnetization of up to ۵۱۰۰ Oe and ۵۵ emu g-۱, respectively.

Keywords:

BaFe۱۲O۱۹ , Permanent magnets , Hexagonal ferrites , Sol-Gel auto -combustion method