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Structure types of MnB2. (a) AlB2- type and (b) ReB2-type structures viewed parallel and perpendicular to the c-axis.
SEM and TEM images of MnB2 synthesized in a piston-cylinder apparatus. (a) The SEM image of crystal with polished surface in back-scattered electrons, indicating its chemical homogeneity, and (b) bright field TEM image of the same sample. The inset corresponds to a selected area electron diffraction pattern of the 〈120〉 zone axis.
The calculated total energy as a function of volume of the AlB2-type (circles) and ReB2-type (squares) MnB2. (a) GGA; (b) GGA + U calculations, the vertical dashed line marks the location of the high-spin–low-spin transition for ReB2-structured MnB2 as found in the GGA + U calculations, and (c) the afm magnetic moment of Mn as a function of volume with GGA (open) and GGA + U (filled symbols).
Total and atom projected DoS calculated for the AlB2 structured MnB2 using (a) GGA and (b) GGA + U. The DoS projected onto the different orbitals of the Mn1 atom in the AlB2-structured MnB2 for (c) GGA and (d) GGA + U. For (c) and (d), only the spin majority states are shown. The DoS are shown at 46 Å3 and 51 Å3 for the GGA and GGA + U calculations, close to the respective ambient pressure volume (Table III ).
Summary of experiments performed for the high pressure synthesis of MnB2.
Experimental data and results of the structure refinement for MnB2 with the AlB2-type structure.
Equation-of-state parameters for the MnB2 phases considered in the current study. The equilibrium volume (V 0), the bulk modulus (K 0), and its pressure derivative (K 0′) are listed. Also given is the magnetic moment at the equilibrium volume for the antiferromagnetic structure.
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