• • • • • • •

F IGU RE 6.6 Schelnatic sketches of the surface configuration of oxygen (dark circles) and carbon monoxide (open circles) adsorbed on Pd (111) surface. (a) Very low concentrations of Dads and COads; (b) formation of islands of the 0 (2 )( 2) and CO (/3 )( /3) R 30° structures [8].