Researchers at the University of Minnesota Twin Cities have demonstrated an unexpected new way to change how a metal behaves electronically. By carefully engineering the atomic interactions where two materials come into contact, the team was able to significantly alter the properties of a metallic material.
The findings, published in Nature Communications, show that a phenomenon known as interfacial polarization can be used to adjust the surface work function of metallic ruthenium dioxide (RuO2) by more than 1 electron volt (eV). The effect was achieved simply by changing the thickness of an ultra-thin film by a few nanometers.
Atomic-Scale Control of Metal Properties
Polarization is typically associated with insulating materials and ferroelectrics rather than metals. However, the researchers found a way to stabilize polarization within a metallic system and use it to influence electronic behavior.
"We often think of polarization as something that belongs to insulators or ferroelectrics -- not metals," said Bharat Jalan, professor and Shell Chair in the Department of Chemical Engineering and Materials Science at the University of Minnesota. "Our work shows that, through careful interface design, you can stabilize polarization in a metallic system and use it as a knob to tune electronic properties. This opens an entirely new way of thinking about controlling metals."
