Magnetic domain studies on single-domain particles of the low-temperature phase of MnBi by the colloid-SEM method

Abstract

Abstract Magnetic domains of isolated small particles of the low-temperature phase of MnBi in the ball-milled state after sintering have been studied by the colloid-SEM (scanning electron microscope) method, a modified Bitter method, with magnifications from 10 000 x to 45 000 x. By decreasing the particle size, domain patterns characteristic of the single-domain particles were found. Observations show that the critical size for the single-domain particle is greater than 1 μm which is larger than the theoretical value of about 0·5 μm. This difference is discussed.