Mechanical properties of MAX phase thin films: The effect of band filling on the elastic properties of M2AlC thin Films (M=Ti, V, Cr)

Mn+1AXn相(其中M是早期过渡金属，A是A族元素，X是C或N，n=1-3)具有不寻常的机械、化学、热和电性能的组合。这一组相当独特的性质，即以前未预见到的金属和陶瓷属性的组合的起源是由于它们的纳米层状原子排列。虽然巴苏姆和同事1等人对Ti3SiC2的性质进行了较好的描述，但关于结构相关化合物的合成和性质的许多基本材料科学问题仍然没有得到回答：一个这样的实验未探索的问题是，211Max相中碳化物形成金属M的价电子组态对弹性和塑性性能的依赖。M2AlC系统的选择是基于我们最近发表的从头计算。我们的策略是，一旦确定和优化了这些材料的合适生长条件，就将通过纳米压痕测量的力学性能与通过结构、化学和成键表征获得的信息相关联，以获得M2AlC中碳化物形成金属M的系统变化的价电子组态。通过与已经发表的从头算数据的关联，我们希望对这类迷人的固体有更好的基本理解。

Mn+1AXn phases (where M is an early transition metal, A an A group element and X is either C or N, n=1-3) possess an unusual combination of mechanical, chemical, thermal and electrical properties. The origin of this rather unique set of properties, i.e. a previously unforeseen combination of metallic and ceramic Attributes is due to their nanolaminated atomic Arrangement. While the properties of Ti3SiC2 are comparatively well described by Barsoum and coworkers 1 and others, many basic materials science questions with respect to the synthesis and properties of structurally related compounds remain unanswered: One such experimentally unexplored question is the dependence of the elastic and plastic properties on the valence electron configuration of the carbide forming metal M in 211 MAX phases. The M2AlC system was selected based on our recently published ab initio calculations. Our strategy is, once suitable growth conditions for these materials are identified and optimized, to correlate the mechanical properties measured by nanoindentation with the information gained through structure, chemistry and bonding characterization for the systematically varied valence electron configuration of the carbide forming metal M in M2AlC. Through correlation with already published ab initio data we expect to contribute towards a better basic understanding of this fascinating class of solids.