We have used low energy electron microscopy to monitor the high-temperature behavior of surface phases in the Co/Si(111) system at submonolayer coverages. We observe a reversible phase separation from a disordered “(1×1)” phase to well-defined coexisting regions of ordered (7×7)-reconstructed and disordered phases. The transition temperature is depressed by nearly 200°C by the addition of 0.1 monolayer of cobalt. The shape of the coverage-temperature phase boundary allows us to estimate the latent heat of the (7×7) order-disorder transition.
ASJC Scopus subject areas
- Physics and Astronomy(all)