An investigation was made of the structure, energetics and effects of stacking faults in MgB2 by means of first-principles density functional calculations. Two structurally different stacking faults were found, with displacements of [01/20] and [2/3, 1/3, 0], and formation energies of 956 and 932erg/nm2, respectively. Significant expansions were found at both stacking faults. The partial density of states showed that the B atoms in these stacking faults exhibited large reductions in the density of states around the Fermi energy. Due to their low density, these stacking faults were not expected to cause a significant decrease in the transition temperature.

Structures, Energetics, and Effects of Stacking Faults in MgB2. Y.Yan, M.M.Al-Jassim: Physical Review B, 2002, 66[5], 052502