Impact of annealing temperature on the structural, magnetic and dielectric properties of BaFe 12-x Y x O 19 (x=0.0, 0.2, 0.4, 0.6) nanocrystalline samples

This paper presents an investigation into the structural, magnetic, and dielectric characteristics of BaFe12xYxO19 (x = 0.0, 0.2, 0.4, 0.6) nanoparticles (NPs) produced by the sol-gel method at 800, 900, 1000, 1100 degrees C annealing. Rietveld refinement analysis shows that the lattice parameter ratio (c/a) lies within the range of 3.93-3.96 provides the confirmation of M type hexaferrite with space group P 6 3 / mmc . The average crystallite size for BaFe12O19 is found to decrease (53.0-23.4 nm) with increasing annealing temperature while for doped BaFe 12-x Y x O 19 it is increased from 30.7 to 96.2 nm. The magnetization found to decrease (82-17 emu/g) with Y 3+ content for 800 and 900 degrees C annealing. However, for 1000 and 1100 degrees C annealing the magnetization increases and reaches to maximum 100.2 emu/g for x = 0.2 at 1100 degrees C annealing. The site preference of the Fe3+ ions is responsible to change the value of magnetization. The coercivity of undoped BaFe12O19 varies from 4039 to 2028 with doping content. However, maximum coercivity 4586 Oe is found for x = 0.4 at 900 degrees C. The dielectric function is found to vary with annealing temperature and Y content as well. The wide range of magnetic properties (soft and hard magnetic) can be used in data storage, spintronic and microwave device applications.