Effects of edge passivations on the electronic and magnetic properties of zigzag boron-nitride nanoribbons with even and odd-line stone–wales (5–7 pair) defects

First-principles spin-polarized calculations have been performed on passivated boron-nitride nanoribbons (BNNRs) with pentagon–heptagon line-defects (PHLDs), also called as Stone–Wales line-defects. Two kinds of PHLDs, namely, even-line and odd-line PHLDs, have been added either at one edge or at both edges of BNNRs. Single-edge (with all its different possibilities, for example, for a BNNR with 2-line PHLD at single-edge there are eight possibilities) as well as both-edge passivations have been considered for all the ribbons in this study by passivating each edge atom with hydrogen atom. Density of states (DOS) and projected-DOS analysis have been accomplished to understand the underlying reason for various properties. We find that passivation lead to different effects on the electronic and magnetic properties of a system, and the effects are mainly based on the line-defect introduced and/or on the atoms which are present at the passivated edge. In general, we find that, passivation can play a key role in tuning the properties of a system only when it has a zigzag edge.