Metallic glasses are emerging as potentially useful materials at the frontier of materials science research. They combine the advantages and avoid many of the problems of normal metals and glasses, two classes of materials with a very wide range of applications. For example, metallic glasses are less brittle than ordinary glasses and more resilient than conventional metals. Metallic glasses also have unique electronic behavior that scientists are just beginning to understand. In a new study, scientists at the Carnegie Institution used high pressure techniques to probe the connection between the density and electronic structure of a cerium-aluminum metallic glass, opening up new possibilities for developing metallic glasses for specific purposes.
“High pressure is an extremely powerful tool for understanding these materials,” says Ho-kwang Mao of Carnegie’s Geophysical Laboratory, a co-author of the study published in Physical Review Letters. “Pressure can cause changes in their properties, such as their volume or electronic behavior, which in turn tells us about their structure at the atomic scale. The more we know about the structure, the better we can predict their properties and more quickly we can develop new materials.”
Unlike ordinary metallic materials, which have an ordered, crystalline structure, metallic glasses are disordered at the atomic scale. This disorder can actually improve some properties of the material, because boundaries between crystal grains are often sites of weakness, leading to breakage or corrosion. Metallic glasses can therefore have superior strength and durability as compared to other metals. The disordered structure also makes metallic glasses highly efficient magnets because it lacks the kinds of defects found in crystalline metals.