A COMPARATIVE-STUDY OF ZNOX OVERLAYERS ON CU(311), CU(110), AND A HIGH DEFECT CONCENTRATION CU(111)

Zinc and oxygen were deposited in ultrahigh vacuum to form ZnOx overlayers on three different copper faces, Cu(311), Cu(110), and a high defect concentration Cu(111). Up to 1.0 monolayer of ZnOx overlayers were examined. No long-range order was found for ZnOx overlayers on any of these surfaces. We used a combination of CO and CO2 temperature programmed desorption (TPD), Auger electron spectroscopy (AES), and low-energy electron diffraction (LEED) to follow chemical and structural changes of ZnOx overlayers on copper. Upon heating above 300 K, ZnOx area decreases while copper area increases, indicating clustering of ZnOx. In addition to changes in ZnOx overlayers on copper surfaces, we examined the decomposition of ZnOx to form Zn(g) and O(surface) by a combination of TPD, AES, and LEED. The desorption temperature of zinc vapor from the decomposition of ZnOx depends on the structure of the copper substrate.