An X-ray and neutron diffraction investigation of the magnetic phase Al_0.89Mn_1.11

Structural and magnetic properties of nanostructured Mn–Al–C magnetic materials

“…However, this could be related to greater ordering of the t-phase. The importance of the degree of order for t-MnAlC is well known [2,41,42]. In the ideal stoichiometric CuAu lattice the A and B atoms occupy alternating planes perpendicular to the C-axis, Mn atoms on A sites couple ferromagnetically to each other, but antiferromagnetically to Mn atoms on B sites.…”

Microstructure and magnetic properties of Mn–Al–C alloy powders prepared by ball milling

“…This ferromagnetic phase has body-centered tetragonal structure, in which the Mn atoms occupy the (0, 0, 0) sites and exchange ferromagnetically with each other, while the Al atoms and the Mn atoms in excess with the equiatomic composition take the (1/2, 1/2, 1/2) sites. Mn moments in these two sites exchange antiferromagnetically [8]. The s-phase can be obtained by quenching the high temperature e-phase followed by isothermal annealing from 673 to 973 K. Prolonged annealing results in decomposition of the s-phase to the equilibrium c 2 and b phases [9].…”

Preparation of nanocrystalline Mn–Al–C magnets by melt spinning and subsequent heat treatments

“…The manganese ions are ferromagnetically aligned on (0 0 0) sites whilst on the body centered (1/2, 1/2, 1/2) sites they are anitiferromagnetically coupled with respect to the former. The aluminium ions occupy the remaining (1/2, 1/2, 1/2) sites [2]. Unfortunately, the L1 0 (or )-phase is a metastable one forming from a quenched-in high-temperature hexagonal () parent phase by annealing at 550 • C. The addition of a small amount of carbon stabilizes the tetragonal L1 0 phase and prevents the decomposition of the alloy into the stable but nonmagnetic ␥ (Al 8 Mn 5 ) and ␤ (Mn) phases.…”