二维碳化钛和氮化钛MXe的费米学研究
Fermiology of two-dimensional titanium carbide and nitride MXenes
摘要：
MXene是一类二维过渡金属碳化物和氮化物材料，其通常表现出非常好的金属导电性，因此对于例如，柔性电子、电催化和电磁干扰屏蔽。然而，令人惊讶的是，对MXene的费米学，即费米面的形状和大小及其对材料性质的影响知之甚少。其中一个原因可能是MXene表面几乎总是被官能团的混合物覆盖，并且研究无序系统的费米表面是麻烦的。在这里，我们研究了四种常见的钛基MXene作为表面官能团组成的函数的费米学。我们首先计算了具有显式混合表面的系统的有效能带结构，观察到Ti-d带的填充和由此产生的费米能级移动的逐渐演化。然后，我们证明，这些能带结构可以通过使用假氢化表面接近，也比较有利的实验角度分辨光电子能谱的结果。通过修改赝氢电荷，然后我们继续绘制所有系统的费米面，并提取它们的属性，如费米表面积和平均费米速度。这些又被用来评估的电导率与弛豫时间拟合实验测量的电导率。
英文摘要：
MXenes are a family two-dimensional transition metal carbide and nitride materials, which often exhibit very good metallic conductivity and are thus of great interest for applications in, e.g., flexible electronics, electrocatalysis, and electromagnetic interference shielding. However, surprisingly little is known about the fermiology of MXenes, i.e, the shape and size of their Fermi-surfaces, and its effect on the material properties. One reason for this may be that MXene surfaces are almost always covered by a mixture of functional groups, and studying Fermi-surfaces of disordered systems is cumbersome. Here, we study fermiology of four common Ti-based MXenes as a function of the surface functional group composition. We first calculate the effective band structures of systems with explicit mixed surfaces and observe gradual evolution in the filling of the Ti-d band and resulting shift of Fermi-level. We then demonstrate that these band structures can be closely approximated by using pseudohydrogenated surfaces, and also compare favorably to the experimental angle-resolved photoemission spectroscopy results. By modifying the pseudohydrogen charge we then proceed to plot Fermi-surfaces for all systems and extract their properties, such as the Fermi-surface area and average Fermi-velocity. These are in turn used to evaluate the electrical conductivity with the relaxation time fitted to experimentally measured conductivities.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
