Image of the Month

January 2008

Sulfite and Sulfate on Ag(111)



RHK Technology SPM 1000 featuring XPMProTM

Imaging condition: PtIr tip, bias voltage 0.3 V, tunneling current 1 nA, 300 K Image sizes: 125×125 nm2, 84×84 nm2 Image description: The sulfite (SO3) and sulfate (SO4) intermediates on
Ag(111) after reacting sulfur dioxide with the Ag(111)-p(4×4)-O surface oxide at 300 K. Surface sulfite orders as the (2√3×2√3)R30° hexagonal structures, and surface sulfate forms the stripe structures. The topographic nanorestructuring of the surface in the reaction shows unambiguously the mass transport and the redistribution of the silver adatoms in the adsorbate layer. The structures of sulfite and sulfate intermediates all contain the incorporated silver adatoms. The monoatomic silver islands are formed by released silver adatoms in the original surface oxide layer.

Courtesy of:
Ling Zhou, Weiwei Gao, and Robert J. Madix – School of Engineering and Applied Sciences, Harvard University