Why do grain boundaries exhibit finite facet lengths?
نویسندگان
چکیده
Uniform finite facets are frequently observed at grain boundaries (GBs) and are usually attributed to equilibrium stabilization by GB stress. We report calculations for an aluminum twin GB using density functional theory, the embedded-atom method, and continuum elasticity theory. These methods show that GB stress is much too small to stabilize finite facets, suggesting that the usual explanation is incorrect.
منابع مشابه
High resolution mapping of oxygen reduction reaction kinetics at polycrystalline platinum electrodes.
The scanning droplet-based technique, scanning electrochemical cell microscopy (SECCM), combined with electron backscatter diffraction (EBSD), is demonstrated as a powerful approach for visualizing surface structure effects on the rate of the oxygen reduction reaction (ORR) at polycrystalline platinum electrodes. Elucidating the effect of electrode structure on the ORR is of major interest in c...
متن کاملNumerical Study of Grain Boundary Diffusion: Size Effects
1. Introduction Enhanced diffusivities along grain boundaries (GBs) are highly relevant for the preparation as well as for the performance of many polycrystalline materials. The importance of GBs is even further increased, if materials are characterized by a high density of interfaces. In such cases, for example in nanocrystalline materials, experiments to determine diffusion coefficients are n...
متن کاملFinite Element Modeling of Strain Rate and Grain Size Dependency in Nanocrystalline Materials
Nanocrystalline materials show a higher strain-rate sensitivity in contrast to the conventional coarse-grained materials and a different grain size dependency. To explain these phenomenon, a finite element model is constructed that considers both grain interior and grain boundary deformation of nanocrystalline materials. The model consist of several crystalline cores with different orientations...
متن کاملHelium bubble formation in ultrafine and nanocrystalline tungsten under different extreme conditions
We have investigated the effects of helium ion irradiation energy and sample temperature on the performance of grain boundaries as helium sinks in ultrafine grained and nanocrystalline tungsten. Irradiations were performed at displacement and non-displacement energies and at temperatures above and below that required for vacancy migration. Microstructural investigations were performed using Tra...
متن کاملDynamics of Carrier Transport in Nanoscale Materials: Origin of Non-Drude Behavior in the Terahertz Frequency Range
It is known that deviation from the Drude law for free carriers is dramatic in most electronically conductive nanomaterials. We review recent studies of the conductivity of nanoscale materials at terahertz (THz) frequencies. We suggest that among a variety of theoretical formalisms, a model of series sequence of transport involving grains and grain boundaries provides a reasonable explanation o...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Physical review letters
دوره 90 24 شماره
صفحات -
تاریخ انتشار 2003