氧、硫掺杂六方氮化硼单层的第一性原理计算

采用基于密度泛函理论和投影缀加平面波的第一性原理计算方法, 研究了六方氮化硼单层(h-BN)中的氮原子缺陷(V_N)、氧原子取代氮原子(O_N)和硫原子取代氮原子(S_N)时的几何结构、磁性性质和电子结构.研究发现, V_N和O_N体系形变较小, 而S_N体系形变较大; h-BN本身无磁矩, 但具有N缺陷或者掺杂后总磁矩都是1 μ_B; 同时给出了态密度和能带结构.利用掺杂体系的局域对称性和分子轨道理论解释了相关结果, 尤其是杂质能级和磁矩的产生. 关键词： 六方BN单层 第一性原理计算 密度泛函理论 分子轨道理论

First-principles calculations of h-BN monolayers by doping with oxygen and sulfur

Using first-principles calculations based on density functional theory and projector augmented wave method, we investigate the geometric structures, magnetic properties and electronic structures of h-BN monolayer with nitrogen vacancy (V_N), nitrogen substituted by oxygen (O_N) or sulfur (S_N). The results show that the h-BN monolayer with S_N presents a larger geometric distortion than with O_N and V_N. Although the pure h-BN is non-magnetic, all the systems with defects are magnetic with the magnetization value of 1 μ_B per cell. Spin polarized density of states and energy band structures are presented. By using symmetrical analyses and molecular orbit theory, the formations of impurity energy levels and local magnetic moment are well explained.
Keywords： h-BN monolayer first-principles calculation density functional theory molecular orbital theory