Lead-on-Silicon Growth Over Time (IMAGE) DOE/Ames National Laboratory Caption Lead atoms in liquid-like motion across a silicon substrate. The black region is an area initially without lead, and the outside white area has a full layer of lead. The four images represent snapshots of how the outside layer moves and fills the empty area. (The difference in grey and white is because the new lead atoms that enter the empty area are not yet in their perfect sites.) US Department of Energy Ames Laboratory scientists, in collaboration with scientists from Hong Kong University of Science and Technology, were the first to observe this unique diffusion of lead atoms on a silicon substrate. Credit US Department of Energy's Ames Laboratory Usage Restrictions Please give photo credit as License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.