Design of atomically localized magnetic moment by adatoms chemisorbed on graphene

Abstract

Recent studies have identified that boron adatom chemisorbs on graphene with a weak localized magnetic moment. Using hybrid exchange-correlation functional, we show that P adatom rather than As can also chemically adsorb on the bridge site (Bri) of graphene. However, due to the large local distortion caused by P adsorption, the most energetically favorable site is Hollow (H) site instead with physisorption. Tensile strain (ε) is able to counterbalance the dominant distortion and can switch the stable site from H to Bri when ε exceeds 2.3 %. The corresponding localized magnetic moment is sizable with 1.00 µB, which seems stronger than the case of B adatom. Such apparent spin-polarization stems from the abundant charge transfer from P adatom to graphene. We also find that interlayer coupling of graphene can reduce the threshold of tensile strain significantly. Our findings might extend the atomic scale magnetism on graphene from hydrogen/boron to underlying phosphorus.