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Energy bandstructures of MgB2 and the related compounds

Hisatomo Harima
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Abstract

Energy band structures are calculated for the new superconductor MgB$_2$ and the related compounds by using the LDA and an FLAPW method. It is found that the strong three dimensional network in low-lying $π$ bands brings about two dimensional $σ$ holes in MgB$_2$, which should be responsible for the superconductivity. The de Haas-van Alphen frequencies and the cyclotron masses are obtained for the Fermi surfaces. The $σ$ hole is not found in LiBC due to the less three dimensional network. MgB$_2$C$_2$ is found a semiconductor, but the top of the valence bands are similar to the $σ$ bands in MgB$_2$. The total energy calculations are also performed for Mg$_{1-x}$Al$_x$B$_2$ to investigate the structural phase instability, experimentally observed around $x=$10%.

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Hisatomo Harima. 2002-01-25. Energy bandstructures of MgB2 and the related compounds. https://doi.org/10.1016/s0921-4534(02)01375-8

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