Rice University researchers have discovered that sheets of hexagonal boron nitride (h-BN) as little as one atom thick can protect metals in harsh environments at up to 1,100 degrees Celsius. The top image shows uncoated nickel oxidized after exposure to high temperature in an oxygen-rich environment. The second shows nickel exposed to the same conditions with a 5-nanometer coat of h-BN. The third shows electron microscope images of two, three, four and many-layer h-BN films. The bottom image of an h-BN sheet shows the hexagonal arrangement of nitrogen (bright) and boron atoms.