Analysis of the demagnetization process of Nd–Fe–B sintered magnets at elevated temperatures by magnetic domain observation using a Kerr microscope

2014/02/25 by M. Takezawa, H. Ogimoto, Hirofumi OGIMOTO +3
Materials Science · Physics and Astronomy · #Magnetic Properties of Alloys #Magnetic Properties and Applications #Magnetic properties of thin films

paper · pdf · doi:10.1063/1.4866894

Abstract

Magnetization reversal and its propagation in sintered Nd–Fe–B magnets were clearly observed at elevated temperatures up to 150 °C using a Kerr microscope, image processing, and photo editing. Simultaneous magnetization reversal in several grains along the easy axis direction occurred at elevated temperature, and the extent of simultaneous magnetization reversal increased with temperature. This indicates that reduction in the coercivity of Nd–Fe–B sintered magnets at elevated temperatures is attributable to decrease in anisotropy and insufficient pinning of domain walls at grain boundaries.

Related

• Magnetic domains in sintered Fe-Nd-B magnets
• Nanoanalytical TEM studies and micromagnetic modelling of Nd-Fe-B\n magnets
• Magnetization processes in two different types of anisotropic, fully dense NdFeB hydrogenation, disproportionation, desorption, and recombination magnets
• Micromagnetic simulations of Nd-Fe-B hot-deformed magnets subjected to eutectic grain boundary diffusion process
• Effect of Al-Zn alloy wafer grain boundary diffusion on the magnetism and microstructure of sintered NdFeB magnets