基于第一性原理对平面内化学有序原子层状材料（MoSc）AlC和（MoY）AlC的研究。

An investigation of the in-plane chemically ordered atomic laminates (MoSc)AlC and (MoY)AlC from first principles.

作者信息

Thore A, Rosen J

机构信息

Thin Film Physics, Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping, Sweden.

出版信息

Phys Chem Chem Phys. 2017 Aug 16;19(32):21595-21603. doi: 10.1039/c7cp03228e.

DOI:10.1039/c7cp03228e

PMID:28766605

Abstract

We have calculated electronic, vibrational, and elastic properties of (MoSc)AlC and (MoY)AlC, two recently discovered nanolaminated materials in the family of so-called i-MAX phases. A comparison is made to the properties of the related hypothetical MAX phases ScAlC, YAlC, and MoAlC. From an analysis of the electronic band structures and projected crystal orbital Hamilton populations (pCOHP), we show that the i-MAX phases have more isotropic band structures than the MAX phases, but that their bonding characteristics are very similar, despite belonging to different space groups. However, the similar bonding notwithstanding, qualitative as well as significant quantitative differences are seen in the phonon density of states (PDOS). We also compare the Voigt-Reuss-Hill (VRH) bulk, shear, and Young's moduli. For (MoSc)AlC, B = 132 GPa, G = 89 GPa, and E = 218 GPa, all of which are higher values than for ScAlC, but lower than for MoAlC. For (MoY)AlC, B = 117 GPa, G = 85 GPa, and E = 205 GPa, which are higher than for YAlC, but lower than for MoAlC.

摘要

我们计算了（MoSc）AlC和（MoY）AlC的电子、振动和弹性性质，这两种材料是最近在所谓的i-MAX相家族中发现的纳米层状材料。并将其与相关的假设MAX相ScAlC、YAlC和MoAlC的性质进行了比较。通过对电子能带结构和投影晶体轨道哈密顿布居（pCOHP）的分析，我们表明，i-MAX相比MAX相具有更各向同性的能带结构，尽管它们属于不同的空间群，但其键合特征非常相似。然而，尽管键合相似，但在声子态密度（PDOS）方面仍存在定性以及显著的定量差异。我们还比较了Voigt-Reuss-Hill（VRH）体模量、剪切模量和杨氏模量。对于（MoSc）AlC，B = 132 GPa，G = 89 GPa，E = 218 GPa，所有这些值都高于ScAlC，但低于MoAlC。对于（MoY）AlC，B = 117 GPa，G = 85 GPa，E = 205 GPa，这些值高于YAlC，但低于MoAlC。