How to measure atomic diffusion processes in the sub-nanometer range
How to measure atomic diffusion processes in the sub-nanometer range
复制标题
如何测量亚纳米范围内的原子扩散过程
DOI：
10.1016/j.actamat.2007.10.005
复制
发表时间：
2008
期刊：
影响因子：
9.4
通讯作者：
M. Bruns
中科院分区：
文献类型：
--
作者：
H. Schmidt;M. Gupta;T. Gutberlet;J. Stahn;M. Bruns
Self-diffusion of the atomic constituents in the solid state is a fundamental transport process that controls various materials properties. With established methods of diffusivity determination it is only possible to measure diffusion processes on a length scale down to 10nm at corresponding diffusivities of 10−23m2s−1. However, for complex materials like amorphous or nano-structured solids the given values are often not sufficient for a proper characterization. Consequently, it is necessary to detect diffusion length well below 1nm. Here, we present the method of neutron reflectometry on isotope multilayers. For two model systems, an amorphous semiconductor and an amorphous metallic alloy, the efficiency of this method is demonstrated to detect minimum diffusion lengths of only 0.6–0.7nm. It is further shown that diffusivities can be derived which are more than two orders of magnitude lower than those obtainable with conventional methods. Prospects of this method in order to solve actual kinetic problems in materials science are given.
