THE GROWTH OF CR ON CU(001) AND AG(001) STUDIED BY SCANNING-TUNNELING-MICROSCOPY

We report here the study of the growth of Cr on Cu(001) and Ag (001) b y scanning tunneling microscopy as a function of temperature. The grow th of Cr on Cu(001) was over the temperature range 285 to 575 K, while for Ag(001) it was between 285 and 440 K. The deposition on Cu(001) i s characterised by three dimensional growth and the formation of irreg ular multilayer high islands. With increasing temperature the chromium becomes more particulate and bulk-like in form and develops into larg e surface outgrowths. Films grown at lower temperature and subsequentl y annealed agglomerate indicating that they are metastable. The growth on Ag(001) shows some similarity to that on Cu(001) at ambient condit ions but at elevated growth temperatures Ag overlayers start to form a nd cover the increasingly particulate chromium.