Atomic Resolution Images of Solid-Liquid Interfaces

A scanning tunneling microscope (STM) can provide atomic-resolution images of solids covered with a variety of liquids, including cryogenic fluids, both polar and nonpolar solvents, conductive aqueous solutions, oils, and even greases. This short overview includes images of solids covered with liquid nitrogen, liquid helium, paraffin oil, silicone oil, microscope immersion oil, silicone vacuum grease, fluorocarbon grease, glycerol, and salt water. These images show atoms, charge-density waves, grains in an evaporated metal film, and even corrosion processes as they occur in real time. The future includes not only basic research in surface science but also applied research in lithography, lubrication, catalysis, corrosion, electrochemistry, and perhaps even biology.