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 8 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 (pDOS) 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.