Femtosecond optical characterization of MgB/sub 2/ superconducting thin films

We present the fabrication and optical time-resolved photoresponse characterization of MgB/sub 2/ superconducting thin films. The films were prepared on crystalline and flexible substrates by vacuum co-deposition of B and Mg precursors and high-temperature annealing in an Ar atmosphere. The postannealed films exhibited very smooth surfaces and amorphous morphology with nanocrystal inclusions. Optical pump-probe measurements gave the first insight into the carrier dynamics in MgB/sub 2/ by time-resolved experimental studies of the Cooper-pair breaking and thermalization mechanisms.