Researchers have made an important and surprising discovery about the way in which copper is structured.
The finding could have important implications for the design and future use of this and other materials used in a range of applications, including electronics.
The team found that the granular building blocks in the element can never slot together perfectly.
Instead they are rotated, causing them to be misaligned and creating a rough surface.
Previously scientists had thought that grains of materials, comprised of millions of atoms, were packed together with small gaps around them.
But the team at the AMBER materials science centre based at Trinity College Dublin, working with colleagues in Intel, the US and Britain, found this was not actually the case.
The scientists, led by Principal Investigator Professor John Boland, have established that at the nano scale, copper grains actually tilt up and down to create ridges and valleys.
This impacts how these materials are designed, ultimately enabling more efficient devices, by reducing resistance to current flow and increasing battery life in hand-held devices.
This is because the electrical, thermal and mechanical properties of a substance are influenced by how the grains are connected to each other.
The research is published in the journal Science.
"Our research has demonstrated that it is impossible to form perfectly flat nano scale films of copper and other metals," Professor Boland said.
"The boundary between the grains in these materials have always been assumed to be perpendicular to the surface."
"Our results show that in many instances these boundaries prefer to be at an angle, which forces the grains to rotate, resulting in unavoidable roughening."
