Improvement in magnetic properties of La substituted BaFe12O19 particles prepared with an unusually low Fe/Ba molar ratio

► Effect of lanthanum substitution on the phase composition, lattice parameters and magnetic properties of barium hexaferrite has been studied. ► Samples are prepared with different lanthanum amounts and various initial Fe/(Ba+La) ratios {(Ba1−xLax)·n Fe2O3, where 0≤x≤1 and 1≤n≤6)}. ► Optimum La concentration that maximizes the coercivity at 5.73 kOe was determined as x=0.3 in Ba1−xLaxFe12O19 samples ► Saturation magnetization has also been increased by choosing the initial Fe/(Ba+La) molar ratio as 2 (i.e., n=1) with HCl treatment. ► Chemical formula of the sample which has both the highest coercivity and saturation magnetization is determined as (Ba0.64La0.36)Fe10.5O19.89.