Scanning tunneling microscopy observations of benzene molecules on the Rh(111)-(3 × 3) (C6H6 + 2CO) surface

Scanning tunneling microscopy (STM) images of the (3 × 3) superlattice of benzene and carbon monoxide coadsorbed on the Rh(111) surface reveal a well-ordered array of ringlike features associated with individual benzene molecules, while CO is not resolved. Images further show translational domain boundaries, step-edge structures, and evidence for surface diffusion. The origin of the STM image contrast of these molecules and implications for STM imaging of other molecular adsorbates are briefly discussed. © 1988 The American Physical Society.