A Study of Solid CO2 by XPS

High quality solid CO2 films have been grown on a stainless steel cold-finger using a continuous flow liquid nitrogen system. The solid was formed from research grade (99.995% min. purity) CO2 gas using a gas nozzle placed directly over the cold-finger (at a temperature of approximately 77 K). The base pressure in the chamber was less than 5 × 10−10 T prior to deposition and upon gas introduction was increased, using a precision leak valve, to approximately 5 × 10−8 T. Films were grown in this pressure for 1 h. Gas purity was monitored using a Balzers Prisma QMS 300 quadrapole mass spectrometer. The solid CO2 films were characterized using x-ray photolelectron spectroscopy (XPS). The reported spectra include survey and high resolution scans for the major photoelectron peaks.