Theoretical Investigation of Interfaces
Theoretical Investigation of Interfaces
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DOI：
10.1007/978-3-540-47971-0_4
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
S. Gemming;M. Schreiber
中科院分区：
文献类型：
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作者：
S. Gemming;M. Schreiber
正确处理缺陷是材料设计的主要任务之一，因为缺陷会导致待调谐材料的特性与理想晶体的众所周知的特性之间出现理想或有害的偏差。微电子器件的工作得益于巧妙的点缺陷工程，线缺陷控制着塑性变形过程，而界面则决定了复合材料的机械稳定性。尤其是随着当前纳米级材料的发展趋势，界面变得越来越重要；首先，纳米晶体材料的表面积与体积之比大大增加，其次，点或线缺陷的稳定排列需要最小的微晶尺寸，该尺寸可以大于实际的纳米微晶。因此，本章介绍了最常见的接口属性建模方法。我们介绍了界面对称性、结构和分析的基本概念，重点关注理论方法，并概述了当前可用的原子尺度界面特性建模和模拟技术。区分了两种根本不同的界面类型：同相边界性质的讨论集中在氧化物晶界，我们与大量可用的实验观察结果进行了广泛的研究。对于异相边界，给出了非反应性、反应性掺杂和固有反应性边界的示例。特别关注金属和氧化物之间的界面，其中界面上材料性能的差异最为突出，并且可能发生所有三种键合情况：惰性碎片之间的弱粘附、掺杂时的激活粘附和强粘附。
The proper treatment of defects is one of the major tasks in materials design, because defects are responsible for the either desirable or detrimental deviations between the characteristics of the material to be tuned and the well-known properties of an ideal crystal. Microelectronic devices work because of clever point defect engineering, line defects govern plastic deformation processes, and interfaces determine the mechanical stability of composite materials. Especially interfaces gain importance with the current trend towards nanoscale materials; first, the surface-to-volume ratio is strongly increased in nanocrystalline material, and, second, stable arrangements of point or line defects require a minimum crystallite size, which can be larger than the actual nanocrystallites. Thus, the present chapter gives an introduction into the most common approaches for modeling interface properties. We introduce the basic concepts of interface symmetry, structure and analysis with a strong focus on the theoretical methods and give an overview of currently available techniques for the modeling and simulation of the interface properties at an atomic-scale level. Two fundamentally different interface types are distinguished: The discussion of the homophase boundary properties is focussed on oxide grain boundaries, which we studied extensively in comparison with amply available experimental observations. For the heterophase boundaries examples of non-reactive, reactively doped, and inherently reactive boundaries are presented. A special focus lies on the interfaces between metals and oxides where the discrepancy of the material properties across the interface is most prominent and all three bonding situations can occur: weak adhesion between inert fragments, activated adhesion upon doping, and strong adhesion.