UV laser-induced desorption of CO from Cr2O3(111). A fully quantum state resolved mapping of the desorbing species

✍ Scribed by K. Al-Shamery; I. Beauport; H.-J. Freund; H. Zacharias

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 634 KB
• Volume: 222
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(94)00316-5

✦ Synopsis

The laser-induced desorption of CO adsorbed on an epitaxiahy grown film of Cr203 ( 111) has been studied using 193 nm ( 6.4 eV) laser light. The velocity flux distributions of the desorbing neutral CO in its ground electronic state were recorded quantum state speciticahy by making use of a (1 + 1') REMPI (resonance enhanced multiphoton ionization) technique. Single rovibrational states of the desorbing CO could be selected by using the (B 'Z+ +X 'Z+ ) transition in the WV at zz 115 nm for the first excitation step of the REMPI process. Excellent resolution was obtained in contrast to the most commonly used (2 + 1) REMPI process for the same intermediate state. The velocity flux distributions were bimodal for U" = 0 and monomodal for Y" = 1. The high desorption cross section of (3.5 k 1) x 10-l' cm* is typical for the desorption from oxide surfaces.