We used variable-temperature scanning tunneling microscopy to investigate two types of Ce-induced 5 x 2 structures reconstructed on Si(111) at coverages of 0.5 ML (low) and 3.0 ML (high) after annealing at 600 degrees C. At both Cc coverages, one-dimensional atomic chains formed upon Ce deposition on Si(111). The atomic densities of Ce in the one-dimensional chains varied with Ce deposition coverage. Based on the scanning tunneling microscopy images, we suggest two structural models of the one-dimensional Cc atomic chains. (c) 2005 Elsevier B.V. All rights reserved.