Multilayer influences on the monolayer structure for NO on Pt{110}-(1x2)

The adsorption of NO on Pt{110}-(1 x 2) has been studied in detail in the temperature range from 30 to 400 K. At 30 K, physisorbed multilayers of (NO)(2) are formed after high exposures of NO to the surface. It is found that the presence of physisorbed multilayers influences the underlying chemisorbed adlayer. After heating a surface that contains both chemisorbed and physisorbed NO species, to remove the multilayer, only an atop NO species remains. This species is less stable than bridged NO at low coverages. After annealing a surface on which only chemisorbed NO is present, both atop NO and bridged NO are observed. Hence the physisorbed overlayer partially incorporates into the chemisorbed layer to produce an unusually dense monolayer.