Kinetic processes in the growth and decomposition of a two-dimensional binary alloy

The growth and decomposition of a two-dimensional cobalt-chromium binary al loy on the W(110) surface were studied with scanning tunneling microscopy. At room temperature, co-deposited cobalt and chromium were found to grow in a homogeneous nucleation scheme. At the annealing temperature of 150 degre es C, the co-deposited films decompose into two phases, cobalt-rich and chr omium-rich phases, showing good agreement with the reported phase diagram. In the decomposed film with 0.9 monolayer of cobalt and 0.2 monolayer of ch romium, the second-layer islands are cobalt-rich phases. (C) 1999 Elsevier Science B.V. All rights reserved.