Ab-initio investigations on physisorption of alkaline earth metal atoms on monolayer hexagonal boron nitride (h-BN)

作者：Rafique, Muhammad; Unar, Mukhtiar A.; Ahmed, Irfan; Chachar, Ali R.; Shuai, Yong^*

来源：Journal of Physics and Chemistry of Solids, 2018, 118: 114-125.

DOI：10.1016/j.jpcs.2018.03.007

• Adsorption
• AEM atoms
• h-BN
• Magnetic moments
• Absorption

First-principles density functional theory (DFT) calculations are performed on the structural, electronic, magnetic and optical properties of alkaline earth metal (AEM) atoms-adsorbed hexagonal boron nitride (h-BN) structures. Different AEM atoms were adsorbed on the hollow (H) and bridge sites of monolayer h-BN and their effects on aforementioned properties were then investigated. Calculated adsorption energies indicate that, the physisorption of ARM atoms on h-BN layer is thermodynamically favorable. It is also observed that, the charge transfer occurs from AEM atoms to the h-BN layer. When AEM atoms were adsorbed at H-site of h-BN layer, only Mg and Sr atom adsorption introduced significant magnetic moments of 2.0 mu(B) and 1.0 mu(B) , respectively. During AEM atoms adsorption at bridge site, Ca, Mg and Sr atoms adsorption induced 1.92 mu(B) , 1.98 mu(B) and 0.712 mu(B) magnetic moments in h-BN layer, respectively. Through electronic structure calculations, it is observed that, AEM atom adsorption on h-BN significantly modifies its band structure, by converting wide bandgap h-BN semiconductor to the half metal and/or semimetal. Through density of states (DOS) plots, it is revealed that, s and p orbitals of AEM atoms are mainly responsible for arising of magnetic moments in monolayer h-BN. Finally, the optical parameters specifically, absorption coefficient and reflectivity plots for AEM atoms adsorbed h-BN structures were obtained using DFT within random phase approximation (RPA). Pure h-BN layer presents zero absorption coefficient and low static reflectivity in low lying energy range. However, AEM atom adsorption on h-BN layer produces an increment in absorption coefficient quantity in 0-4 eV energy interval. Similarly, the higher reflectivity parameter is obtained in lower energy range. These obtained results predict that, the AEM atom adsorption on monolayer h-BN carries potential applications for nanoelectronics, spintronic and optoelectronic device applications.

• 出版日期2018-7
• 单位哈尔滨工业大学