Influence of substitutional defects on the structural and magnetic properties of barium hexaferrites
Bilal Aladerah, Maen Gharaibeh, Abdalla Obeidat
Abstract
Abstract A computational analysis is conducted to understand the impact of Al and Sr substitutions on the structural and magnetic properties of M-type barium hexaferrite (BaFe 12 O 19 or BFO). Al substitutions in BFO led to concentration-dependent increases in lattice parameters and magnetocrystalline anisotropy energy ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>E</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="italic">MCA</mml:mi> </mml:mrow> </mml:msub> </mml:math> ), while the magnetic moment showed a decline. In contrast, Sr substitutions influenced the lattice differently, reducing parameters but enhancing both <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>E</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="italic">MCA</mml:mi> </mml:mrow> </mml:msub> <mml:mspace width="1em"/> </mml:math> and the spin magnetic moment, especially under varying Coulomb interaction ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>U</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="italic">eff</mml:mi> </mml:mrow> </mml:msub> </mml:math> ) conditions. It’s noteworthy that the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>E</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="italic">MCA</mml:mi> </mml:mrow> </mml:msub> </mml:math> value reached approximately 1.03 meV with full Sr substitution. Furthermore, SrFe 12 O 19 (SFO) consistently outperformed BFO in terms of exchange interaction parameters. These findings offer valuable insights for the development and optimization of next-generation magnetic materials.