Paper GR+AS+NS+SS-ThM1
Density Functional Theory Studies of Mechanical and Electronic Properties in 2-D Superlattices Made of Carbon and Boron Nitride Domains

Thursday, October 31, 2013, 8:00 am, Room 104 B

Using density functional theory approaches, we have studied the energies and stresses for edges of SiC and BN nanoribbons and for domain boundaries of graphene-BN superlattices.The SiC and BN armchair nanoribbons show pronounced edge relaxations, which obliterate the 3-family oscillatory behavior of the edge stress reported for graphene. Our calculations show small boundary stresses in graphene-BN superlattices, suggesting that such domain boundaries will not experience severe deformation. We have also found that the C-terminated and Si-terminated zigzag edges in SiC nanoribbons have different compressive stresses which results in different rippling behavior of these edges. Furthermore, we have studied the spin-dependent bandgap in superlattices and investigated its dependence, for each spin component, on the domain width and magnitude and direction of applied strains. These investigations suggest the possibility of opening of a bandgap in one spin component but not the other, a behavior which could be controlled by the synthesizing domains with different widths and by applying strains of prescribed magnitude and directions