TRIGONAL IMAGES OF TRANSITION-METAL ATOMS ADSORBED ON TRANSITION-METAL FCC-(111) SURFACES AND THEIR AVAILABILITY FOR SCANNING-TUNNELING-MICROSCOPY

We analyse the possibilities of using a scanning tunneling microscope (STM) as a complementary tool to a field ion microscope (FIM) for obta ining trigonal images of individual transition metal atoms adsorbed on atomically flat (111) surfaces of FCC transition metals. A calculatio n of STM images shows appreciable trigonal shapes. This should stimula te relevant experimental studies. Orientation of the images with respe ct to substrate atoms has been studied as a function of the character of adsorbed species and interpreted in terms of the calculated local d ensity of states.