Gettering of carbon dioxide by erbium thin films

The interaction of carbon dioxide and erbium thin films is characterized for temperatures in the region of 300 to 9000C and partial pressure of carbon dioxide near 5 x 10-7 Torr. Dynamic film pumping speeds were measured against a mercury diffusion pump of known pumping speed and conductance. A quadrupole mass spectrometer was used to monitor the carbon dioxide flow which originated from a calibrated leak in the 10-6 standard cm3/s range. Data reduction was via a dedicated minicomputer with associated printer/plotter. Temperature ramp experiments with thin erbium films indicated a significant reaction above 3000C. The reaction was preceded by the desorption of water vapor, hydrogen and nitrogen and/or carbon monoxide from the film surface