The Study on Effect of Carbon© on the Electronic Structure of MgBXC(x = 1, 2)

In this work first principle study on electronic structure calculations for MgBC, and MgB 2 C is presented. The density functional theory (DFT) as implemented in Quantum-ESPRESSO was used. The band structure and density of state (DOS) is compared with the already reported MgB 2 . It is clearly observed that the presence of Carbon in both compounds change the Fermi level and the hole bands. In MgB 2 C the Fermi level is higher than MgBC that results in suppression of Tc in MgB 2 C. In MgBC the hole band shifted up from gamma to X direction and this may improve superconductivity of the material. Comparison of the DOS at the Fermi level reveals that  MgBC has the highest value (0.9424 state/cell/ev). Using reasonable approximations, the calculated Tc values are, 27.07k and 41.09k for MgB2C and MgBC respectively. This suggests that Carbon(C) has a better contribution than Boron(B) and MgBC is a good candidate for high Tc. Keywords : Superconductivity, Band structure, Density of state(DOS), Density Functional theory(DFT) DOI : 10.7176/APTA/83-03 Publication date: February 29 th 2020