Structure and Electronic States of the α-Sn(111)-( 2×2) Surface

Abstract

Scanning tunneling microscopy (STM) has been used to study thesurface structure and electronic states of α-Sn(111) films grownheteroepitaxially on InSb(111)A-(2× 2). The wide area STM imageshows a large number of domains existing on the terrace, each having anaverage size of about 100 Å and a period of (2× 2). The magnified image shows evidence of a T₄-adatom and rest-atom pairreconstructed structure for theα-Sn(111)-(2× 2) surface, as expected from the ab initio calculations. Furthermore, the result that the adatom and therest-atom appear simultaneously in the occupied state image can beexplained by the existence of back bond states in the adatomconfiguration.