DR PETER HARRIS / SCIENCE PHOTO LIBRARY DR PETER HARRIS / SCIENCE PHOTO LIBRARY
Nanomagnet. Coloured transmission electron micrograph of the world's smallest bar magnet - a single crystal of nickel inside a nanotube. Nanotubes consist of sheets (green lines) of hexagonally arranged carbon atoms wrapped around each other to form a cylinder with a hollow core up to 15 nanometres wide. To make a nanomagnet, the end of the tube is opened with nitric acid and a solution of nickel nitrate introduced. On heating to 400 degrees C, nickel oxide crystals form in the tube. These are then reduced to nickel metal by adding hydrogen gas. Nanotubes could lead to a range of exotic applications, such as molecular-scale wires for microscopic circuits.
Model release not required. Property release not required.