Scanning tunneling microscopy of stepped single crystal surfaces of gold

Abstract

STM has been used to examine the high index (11,1,1) surface of gold which is vicinal to the (100) oriented surface and makes an angle of 7° with it. The STM images exhibited a distribution of terrace widths ranging typically from 50 to 80 Å with an occasional width of 120 Å. For an ideal Au(11,1,1) surface, the minimum terrace width should involve six atoms with the expected terrace width of 6 × 2.9 = 17.4 A ̊ . The width of the smallest terrace examined on this surface was two to three times larger and the step similarly larger. This may be due to the restructuring of the surface during the flame annealing. The STM results for the Au(755) and Au(322) surfaces also show terraces which vary in length and show evidence of kinks — particularly the Au (755) surface. The various factors which may control the terrace widths are discussed in the paper.