Exploration of Synthesis Conditions for High-Magnetization Ba-Ca-Based W-Type Hexaferrites

This study presents the synthesis of W-type hexagonal ferrite (BaZn<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{2}$</tex-math></inline-formula>Fe<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{16}$</tex-math></inline-formula>O<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{27}$</tex-math></inline-formula>) using a powder metallurgy approach to enhance magnetic properties through controlled Ca doping. By identifying the crystalline phase and repeating to adjust the composition, we achieved a primary-phase W-type hexaferrite substituted with about Ba: Ca = 0.5: 0.5 in the chemical formula. Electron probe microanalysis results helped us reach the sample with Ba: Ca: Zn: Fe = 0.52: 0.48: 0.78: 10.73, demonstrating the highest magnetization of 131.0 A<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\cdot$</tex-math></inline-formula> m<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{2}$</tex-math></inline-formula>/kg at 1.8 K. Our findings suggest the magnetically optimal nature of this composition for Ca-substituted Ba-based W-type ferrite. This investigation contributes to understanding Ba-Ca-based W-type hexaferrite and provides a foundation for future exploration and optimization of its magnetic properties.