Investigating the effects of Carbon and Boron atoms on the t- MnAl alloy properties employing the first principle approach

Abstract

Permanent magnet-based technologies are focusing on the use of t-phase magnetic alloys. The t-MnAl permanent magnetic alloys are interesting candidates to fill the performance gap between the expensive rare-earth-based magnets and the low performance ferrites. The purpose of the study was to investigate the effects of carbon and boron on the structural, electronic and magnetic properties of t-MnAl using the first principle method. The first principle calculations were performed using the density functional theory (DFT) within the generalized gradient approximation (GGA), with the perdew-burke-eruzer (PBE) function for exchangecorrelation potential employed in CASTEP to study the electronic, and magnetic properties of tMnAl magnets. The study revealed that t-MnAl have a total magnetic moment of 3.04µB, where Mn and Al have 2.69µB and 0.35µB respectively. A decrease in magnetic moment of Mn from 2.69µB to 1.51µB was obtained adding B atoms. The DOS of t-MnAl was observed to have a lower peak at the fermi level. The magnetic moment obtained for Mn was 0.46µB after C atoms were added. The DOS of Mn3AlC shifted to the right with the highest peak at the fermi level. The results obtained revealed that the DOS of t-Mn2AlB2 and t-Mn3AlC have their highest peaks at the fermi level. This was due to the decrease in magnetic moment of Mn after adding C and B to t-MnAl.