  We show that by annealing Ga1-xMnxAs thin films at temperatures significantly
lower than in previous studies, and monitoring the resistivity during growth,
an unprecedented high Curie temperature Tc and conductivity can be obtained. Tc
is unambiguously determined to be 118 K for Mn concentration x=0.05, 140 K for
x=0.06, and 120 K for x=0.08. We also identify a clear correlation between Tc
and the room temperature conductivity. The results indicate that Curie
temperatures significantly in excess of the current values are achievable with
improvements in growth and post-growth annealing conditions.
