Speaker
Description
In this work, the different sizes of LTP-MnBi powder prepared by vacuum sintering at 275ºC and time for 12 hr. responds to the magnetic properties, microstructure, and crystal structure. Cross-sectional MnBi powder particles were prepared for investigations by using scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (SEM/EDS). The SEM/EDS results provide information of the formation of MnBi during liquid phase sintering. The formation mechanism will be presented and discussed. Magnetic force microscopy (MFM) was also employed to obtain the magnetic properties of the MnBi. The topography and MFM images of the MnBi samples with and without applied magnetic field were recorded. Before applying the field, MFM image shows the bright and dark regions of the magnetic domain similar to SEM/EDS image that displayed a spider-web feature of the MnBi phase and Mn phase. With aligned magnetic field, the size of the magnetic domain split into the small domain. The small MnBi grain size, the higher coercivity.
Keyword: LTP-MnBi, vacuum sintering, MFM, magnetic domain, domain wall movement
