Carbon Joins the Magnetic Club

A carbon film is hit by a high-energy proton beam, causing the magnetic moments of the atoms to align around the beam impact area and creating a ring-shaped magnetic pattern that can be imaged with a magnetic-force microscope. The X-ray microscope can also be tuned to "scan" the sample for magnetism associated with other elements. The absence of a ring pattern in scans for cobalt, nickel and iron prove that the sample contains only carbon. Credit: SLAC