True atomic resolution in liquid by frequency-modulation atomic force microscopy

True atomic resolution of frequency-modulation atomic force microscopy in liquid is demonstrated. Hexagonal lattice of a cleaved (001) surface of muscovite mica is resolved in water. Nonperiodic structures such as defects and adsorbates are simultaneously imaged with the atomic-scale features of mica surface. The use of small oscillation amplitude (0.16-0.33 nm) of a force sensing cantilever allows us to obtain vertical and lateral resolutions of 2-6 and 300 pm, respectively, even with a low Q factor in water (Q=20-30). (c) 2005 American Institute of Physics.