Improving our Understanding of Material Interfaces
Sometimes when you put two things together you can get something greater than the sum of its parts, because of how the two pieces interact. In materials science the interface of two materials can actually have completely different properties from those of the component materials. Curiously though these properties can be significantly different than theory predicts, but researchers at Deutsches Elektronen-Synchrotron have finally found out why that may be.
For this research, the researchers examined strontium titanate and lanthanum aluminate, which are insulators on their own, but the interface between them is conductive. This comes from the materials affecting each other when in close proximity, actually causing some rearrangement. The problem is that it is only a tenth as conductive as it should be, according to Maxwell's theory. By using the DORIS III synchrotron radiation source, the DESY researchers used ultraviolet light to find why this is. It turns out the problem has been that only a tenth of the expected electrons actually came to the interface to form a conductive layer. How many come depends on the number of unit cells within the crystal lattice of the lanthanum aluminate, which means that by altering the structure of the material, the conductance can also be controlled.
Though the research was only done with a specific pairing of materials, it could be applied to any interface between different materials. Eventually that could give us a way to produce and control special properties for use in solar panels, hard drives, superconductors, and more.
Source: Deutsches Elektronen-Synchrotron