STRUCTURE OF THE INSB(111)A-(2-ROOT-3X2-ROOT-3)-R30-DEGREES SURFACE AND ITS DYNAMICAL FORMATION PROCESSES

We have studied the structure of the InSb(111)A-(2 root 3 x 2 root 3)- R30 degrees surface and how it is transformed from the original (2x2) surface under Sb-rich conditions, by using scanning tunneling microsco py, Anger electron spectroscopy, and reflection high-energy electron d iffraction. In the 2 root 3 structure a Sb trimer settles its center o n the In vacancy site of the (2x2) surface, and the three In atoms are further missing from it. These missing In atoms are consumed in a way that, while Sb is deposited onto the (2x2) surface at 230 degrees C, the 2 root 3 surface grows along a direction normal to the step edge, increasing the terrace area and causing the step edge to become ragged .