Experimental studies of the vapor phase nucleation of refractory compounds. V. The condensation of lithium

Lithium nucleation was studied over the range of 830-1100 K in a gas evapor ation apparatus yielding supersaturation ratios of approximately 300 to 7 o ver this temperature range, respectively, at an estimated flux of 10(9) cm( -3) s(-1). During runs we observed the same fluorescence phenomena due to a tomic lithium vapor and the lithium dimer as noted by other researchers. Th e measured supersaturations are much higher than the values predicted by Cl assical Nucleation Theory. Modifications to Classical Nucleation Theory to account for the presence of dimers in the lithium vapor do not seem to acco unt for this discrepancy. The data and Scaled Nucleation Theory agree fairl y well at the lower temperature range, but at the higher end of the tempera ture range the data have a steeper drop in the supersaturation values than predicted by Scaled Nucleation Theory. (C) 2000 American Institute of Physi cs. [S0021-9606(00)01234-4].