Which Transition Metal Atoms Can Be Embedded into Two-Dimensional Molybdenum Dichalcogenides and Add Magnetism?
Which Transition Metal Atoms Can Be Embedded into Two-Dimensional Molybdenum Dichalcogenides and Add Magnetism?
复制标题
DOI：
10.1021/acs.nanolett.9b01555
复制
发表时间：
2019-07-01
期刊：
影响因子：
10.8
通讯作者：
Krasheninnikov, Arkady V.
中科院分区：
文献类型：
--
作者：
Karthikeyan, J.;Komsa, Hannu-Pekka;Krasheninnikov, Arkady V.
与块状固体相比，二维（2D）材料的大的表面与体积比可以为通过例如气相沉积将杂质后合成引入到这些系统中打开新的机会。然而，它对石墨烯或h-BN不起作用，因为掺杂剂原子更喜欢聚集在材料的表面上，而不是整合到原子网络中。使用广泛的第一性原理计算，我们表明，违反直觉的大多数过渡金属（TM）原子可以嵌入到原始的钼二硫属化物（MoDC）的原子网络后，在中等温度下的原子沉积作为替代或替代杂质，特别是在MoTe 2，它具有最大的主机原子之间的间距。我们进一步证明，许多杂质配置有本地化的磁矩。通过分析能量学的趋势和元素周期表中磁矩的值，我们通过TM原子半径和可用于键合的（s + d）电子数的值来合理化结果，并建议最有前途的TM用于在MoDC中诱导磁性。我们的结果与现有的实验数据一致，并应进一步指导实验工作，以实现简单的2D MoDC合成后掺杂，并为这些材料添加新的功能。
As compared to bulk solids, large surface-to volume ratio of two-dimensional (2D) materials may open new opportunities for postsynthesis introduction of impurities into these systems by, for example, vapor deposition. However, it does not work for graphene or h-BN, as the dopant atoms prefer clustering on the surface of the material instead of getting integrated into the atomic network. Using extensive first-principles calculations, we show that counterintuitively most transition metal (TM) atoms can be embedded into the atomic network of the pristine molybdenum dichalcogenides (MoDCs) upon atom deposition at moderate temperatures either as interstitials or substitutional impurities, especially in MoTe2, which has the largest spacing between the host atoms. We further demonstrate that many impurity configurations have localized magnetic moments. By analyzing the trends in energetics and values of the magnetic moments across the periodic table, we rationalize the results through the values of TM atomic radii and the number of (s + d) electrons available for bonding and suggest the most promising TMs for inducing magnetism in MoDCs. Our results are in line with the available experimental data and should further guide the experimental effort toward a simple postsynthesis doping of 2D MoDCs and adding new functionalities to these materials.