Low temperature phases of Pb/Si(111)

In this work the low temperature phases of Pb/Si(111) have been investigate d by means of variable temperature scanning tunneling microscopy (STM). Our STM measurements, performed in the range of 55-215 K, show that two differ ent phases, i.e. Pb/Si(111)-(3 x 3) and Pb/Si(111)-((3)(2)(-1 1)), coexist for samples with a nominal Pb coverage below 1 ML. The general morphology a s well as the atomic structure of both surface reconstructions are discusse d and compared to previous results. (C) 2001 Elsevier Science B.V. All righ ts reserved.