  Heat capacities measured for Al45- and Al47- nanoclusters have reproducible
jumps at ~ 200 K. These jumps are consistent with theoretical predictions that
some clusters with highly degenerate electronic states near the Fermi level
will undergo a transition into a high Tc superconducting state. An analysis
based on a theoretical treatment of pairing in Al45- and Al47- agrees well with
the experimental data in both the value of the critical temperature and in the
size and width of the jumps in the heat capacity.
