Physical properties of boron based crystal structures

The structural, electronic and mechanical properties of some elemental boron phases, boron carbide, metal-boron compounds with different structural units and radioactive element-bor compounds were investigated by first-principles calculations within density functional theory. From results of first-principles calculations, hardnesses of boron-rich or boron-including phases were calculated. The nature of hardness in these phases was discussed. The relations between hardness and mechanical properties such as bulk modulus, shear modulus were studied. Applying hydrostatic pressure at the wide range on the phases, it was investigated that how change structural, electronic and mechanical properties.