Assignment of the electronic transitions in B 4.3C boron carbide implies a specifically distorted crystal structure

摘要

The reversible high-pressure phase transition in boron carbide, making this opaque solid glasslike transparent, the visualization of actual structural distortions in the form of atomic arrangements replacing the three-atomic chain in the unit cell, and the electronic DOS calculated for realistic structure models require re-interpretation of the well-known electronic transitions. – The excellent correlation with a selected distorted structure model, proposed by Ektarawong, assuming that the polar C atoms are randomly distributed over all polar sites of the icosahedra, suggests this model to be close to the actual structure. Assignment between electronic properties and structural peculiarities enables solving some open problems, for example, the nature of the high-pressure phase transition. According to Rasim, some boron-rich components replacing a certain share of three-atomic exhibit negative energies; thus they reduce the total energy and make B4.3C the most stable structure.