Publications

Studies of atomic diffusion in binary alloys by X-ray Photon Correlation Spectroscopy with particular attention to B2 phases

Author(s)
Markus Stana
Abstract

The way single atoms change places in a condensed system determines many of its properties. Insight into the mechanisms controlling such processes, therefore, yields a better understanding of matter which in turn allows for improving fabrication and tailoring of material properties. Intermetallic alloys have many attractive features for industrial applications, such as high specific strength, good corrosion and oxidation resistance and low raw material cost. Their application is, however, still strongly limited by properties such as high brittleness at low temperatures.
Methods capable of studying diffusion on an atomistic level have been restricted to high temperatures close to the melting point of intermetallics until now. The new method of atomic-scale X-ray Photon Correlation Spectroscopy provides a means of studying these materials at technically relevant working temperatures. This thesis demonstrates the application of this new technique to binary intermetallic alloys.
In the first part the theoretical concepts underlying atomic-scale X-ray Photon Correlation Spectroscopy such as correlation, rate equations, scattering and reciprocal space will be thoroughly discussed. As computer simulation techniques play an important role in data evaluation, a chapter is dedicated to this topic. The experimental preconditions are then treated. The last chapters are devoted to the presentation of experimental results. It is shown that a new diffusion mechanism is required to explain atomic hops at relatively low temperature in a B2 Fe-Al alloy with a few percent of excess Fe, while in a B2 Ag-Mg alloy with excess Ag commonly known mechanisms can explain the observed diffusion behavior.

Organisation(s)
Dynamics of Condensed Systems
No. of pages
147
Publication date
2015
Austrian Fields of Science 2012
103009 Solid state physics, 103015 Condensed matter, 103018 Materials physics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/studies-of-atomic-diffusion-in-binary-alloys-by-xray-photon-correlation-spectroscopy-with-particular-attention-to-b2-phases(e4842f02-4eb2-484d-8886-030d8c6820be).html