NaCl multi-layer islands grown on Au(111)-(22 x root 3) probed by scanning tunneling microscopy

The growth of multi-layer NaCl islands on Au(111)-(22 x root 3) surfaces was investigated using scanning tunneling microscopy (STM). We observed that the aspect of the NaCl islands drastically differs depending on the tunneling conditions. It is therefore possible to observe the layers forming an NaCl island or to image the gold reconstruction below the first NaCl layer. Atomically resolved STM images obtained on the first NaCl layer demonstrate that NaCl grows as an epitaxial crystalline film on Au(111)-(22 x root 3). STM images also suggest that some NaCl layers can be non-crystalline.