The field reversal method was used to study the kinetics of Cs and Cs+ desorption from a pyrolytic graphite basal surface. Double-exponential decay was observed especially at high temperatures. Desorption of ions using an external flux from a Cs beam gave the primary rate parameters 2.60eV and 5.3 x 1014/s at 1100 to 1600K. The secondary rate parameters were 0.28eV and 2.2 x 105/s, observed at 1250 to 1600K. Due to the high sensitivity of the method, the kinetics of desorption of the previously absorbed Cs, diffusing out from the bulk crystal, could also be studied. These processes were more complex, giving the primary rate parameters 1.87eV and 1.1 x 1014s, and the secondary rate parameters 2.07eV and 1.97 x 1011/s-1 at 1400 to 1600K. The variation of the primary and secondary rates and the field reversal peak heights as functions of retarding field time were also studied, as well as the field reversal peak variation with temperature. These results, as well as the ones found in previous studies of this system, indicate the existence of three adsorbed states on the more or less polycrystalline graphite surface. One apparently ionic state correlated with the diffusing state in the crystallites and with ionic states outside the surface. Conversion processes to and from this state, induced by the external field, were also observed.

Cesium Ion Desorption from Graphite Surfaces: Kinetics and Dynamics of Diffusion and Desorption Steps. Möller, K., Holmlid, L.: Surface Science, 1986, 173[1], 264-82