Researchers have discovered that a very small change at the atomic level can significantly alter how a metal behaves, opening new possibilities for advanced electronics and materials design.

A team at the University of Minnesota Twin Cities found that carefully controlling the interaction between two materials at their interface can dramatically change the electronic properties of a metal.

Their study, published in ‘Nature Communications’, shows that a process known as interfacial polarization can be used to tune the surface work function of ruthenium dioxide (RuO₂) by more than 1 electron volt. The change was achieved simply by adjusting the thickness of an ultra-thin film by just a few nanometres.

Researchers said the finding challenges the long-held belief that polarization mainly occurs in insulating or ferroelectric materials, not metals.

“We often think of polarization as something that belongs to insulators or ferroelectrics — not metals,” said Bharat Jalan. “Our work shows that, through careful interface design, you can stabilise polarization in a metallic system and use it to tune electronic properties.”

The effect was found to depend strongly on thickness, with the most significant change occurring when the ruthenium dioxide layer reached around four nanometres — roughly the width of a DNA strand.

At this scale, the metal shifts from a strained atomic structure to a more relaxed arrangement, leading to noticeable changes in its electronic behaviour.

“This was surprising,” said Seung Gyo Jeong. “We expected subtle interface effects, but not such a large and controllable change in work function.”

Researchers said the ability to observe and link tiny atomic movements with major electronic changes shows how interface engineering can be used to precisely control metallic materials.

They added that the discovery could have future applications in electronics, catalytic systems and emerging quantum technologies.

Source: Science Daily