Configuration change of NO on Cu(110) as a function of temperature

The bonding structure of nitric oxide (NO) on Cu(110) is studied by means of scanning tunneling microscopy, reflection absorption infrared spectroscopy, and electron energy loss spectroscopy at 6160 K. At low temperatures, the NO molecule adsorbs at the short bridge site via the N end in an upright configuration. At around 50 K, this turns into a flat configuration, in which both the N and O atoms interact with the surface. The flat configuration is characterized by the low-frequency N-O stretching mode at 855 cm(-1). The flat-lying NO flips back and forth when the temperature increases to similar to 80 K, and eventually dissociates at similar to 160 K. We propose a potential energy diagram for the conversion of NO on the surface. (C) 2014 AIP Publishing LLC.