Liu Hanlu, Feng Kehan, Lu Haiming, Meng Xiangkang
College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
Phys Chem Chem Phys. 2022 Mar 30;24(13):7797-7804. doi: 10.1039/d1cp05640a.
Recently, extensive experimental and theoretical studies on two-dimensional materials have attracted enormous interest in exploring the properties of these materials by decorating their surfaces. In the present work, we present a detailed investigation of the structures, and electronic and magnetic properties of pristine, hydrogenated, and fluorinated BeO monolayers using the density functional theory approach. Structurally, the most stable adsorption sites are directly above the host Be atom for half-hydrogenation, above the middle of the Be-O bond for half-fluorination, and directly above the host Be atom and below the host O atom for full-hydrogenation and full-fluorination. Moreover, the electronic and magnetic properties of the BeO monolayer exhibit high sensitivity to chemical functionalization: half-hydrogenation induces nonmagnetic-magnetic transition and the reduction of the band gap reaches about 75%. Full-hydrogenation results in metallization of the BeO monolayer. Half-fluorination makes the BeO monolayer a 100% spin polarized material regardless of the adsorption site. However, depending on different adsorption sites, full-fluorination can produce either magnetically half-metallic or nonmagnetic semiconductor structures. These results demonstrate that the tunability of the electronic and magnetic properties of the BeO monolayer can be realized by chemical functionalization for future nano-electronic and spintronic device applications.
最近，关于二维材料的广泛实验和理论研究引发了人们对通过修饰其表面来探索这些材料性质的极大兴趣。在本工作中，我们使用密度泛函理论方法对原始的、氢化的和氟化的BeO单层的结构、电子和磁性性质进行了详细研究。在结构上，对于半氢化，最稳定的吸附位点直接位于主体Be原子上方；对于半氟化，位于Be - O键中间上方；对于全氢化和全氟化，分别位于主体Be原子上方和主体O原子下方。此外，BeO单层的电子和磁性性质对化学官能化表现出高度敏感性：半氢化诱导非磁性 - 磁性转变，带隙减小约75%。全氢化导致BeO单层金属化。半氟化使BeO单层成为100%自旋极化材料，与吸附位点无关。然而，取决于不同的吸附位点，全氟化可以产生磁性半金属或非磁性半导体结构。这些结果表明，通过化学官能化可以实现BeO单层电子和磁性性质的可调控性，以用于未来的纳米电子和自旋电子器件应用。
