Optimization of magnetic properties: Investigating the interaction of synthesis temperature, particle size, and monodomain formation in barium hexaferrite synthesized by the Pechini method

Abstract

This study presents the synthesis and characterization of barium hexaferrite (BaFe12O19) powders via the Pechini method, employing controlled pH conditions (pH = 1) followed by sintering at temperatures ranging from 800 °C to 1150 °C. Structural and magnetic properties of the samples were investigated using various techniques, including Vibrating Sample Magnetometry, X-ray Diffractometry, and Scanning Electron Microscopy. Additionally,a theoretical analysis was conducted to determine the critical size required for achieving a single magnetic domain in the material. The results reveal a correlation between synthesis temperature and crystal size, ranging from 76 nm (at 800 °C) to 632 nm (at 1150 °C). Notably, samples sintered at 1050 °C exhibited exceptional magnetic properties, displaying a saturation magnetization (Ms) of 75.1 emu/g, a remanent magnetization (Mr) of 36.7 emu/g, and a coercivity (Hc) of 5.65 kOe. The particle size of these samples measured 327 nm, closely aligning with the critical diameter calculated for barium hexaferrite (378 nm) in this study. This optimal critical size was identified in sample sintered at 1050 °C, resulting in notably high coercivity values compared to those reported in previous literature. These findings highlight the significance of synthesis temperature control in tailoring the magnetic properties of barium hexaferrite, offering insights into optimizing its performance for various applications.