Effect of aluminum substitution on microstructure and magnetic properties of electrospun BaFe12O19 nanofibers

Microstructural Characteristics and Magnetic Properties of Al-Substituted Barium Hexaferrite Nanoparticles Synthesized by Auto-Combustion Sol–Gel Processing

“…However, the amount of substituting of Al 3+ ions and also its placement in the hexagonal structure of barium ferrite can be significantly affected on magnetic properties. On the other hand, with substituting Al 3+ ions in the crystal structure of barium ferrite, because of decreasing particle size, H c can be improved [1,2,5]. In the current Fig.…”

“…Barium ferrite has been widely used as permanent magnets, perpendicular magnetic recording media, and electrical and microwave devices [1,4,5]. To achieve these applications, the coercive field (H c ) plays a crucial role.…”

“…To achieve these applications, the coercive field (H c ) plays a crucial role. The coercive field can be remarkably increased with substitution of Fe 3+ by some ions such as Al 3+ [2,5,6], Ce 3+ [7], Cr 3+ [8,9], Ga 3+ [9], Ho 3+ [10], La 3+ [11], Nd 3+ [12,13], etc. As it is well known, in the structure of barium hexaferrite, Fe 3+ ions occupy five nonequivalent sites of which are three octahedral (2a, 4f 2 , and 12k), one trigonal bipyramidal (2b), and one tetrahedral (4f 1 ) [14].…”

“…As it is well known, in the structure of barium hexaferrite, Fe 3+ ions occupy five nonequivalent sites of which are three octahedral (2a, 4f 2 , and 12k), one trigonal bipyramidal (2b), and one tetrahedral (4f 1 ) [14]. These crystallographic sites are coupled by the Fe 3+ -O-Fe 3+ superexchange interaction leading to the ferromagnetic structure [5,13,15]. When Al 3+ ions are entered to the lattice of BaFe 12 O 19 and substitute instead of Fe 3+ ions, the coercive field will be changed with the changing of the magnetocrystalline anisotropy field [2,5].…”

“…These crystallographic sites are coupled by the Fe 3+ -O-Fe 3+ superexchange interaction leading to the ferromagnetic structure [5,13,15]. When Al 3+ ions are entered to the lattice of BaFe 12 O 19 and substitute instead of Fe 3+ ions, the coercive field will be changed with the changing of the magnetocrystalline anisotropy field [2,5]. However, the amount of substituting of Al 3+ ions and also its placement in the hexagonal structure of barium ferrite can be significantly affected on magnetic properties.…”