Experimental studies of oxygen incorporation during growth of Y-Ba-Cu-O films by pulsed laser deposition

We have grown thin films of YBa2Cu3O7-δ in an oxygen atmosphere by pulsed-laser deposition using two synchronized lasers, separated by a variable delay (1μs-10 ms). The ablated fragments from the first laser leads to the formation of a blast wave in O2, leaving behind a rarefied ambient. If the second laser is triggered before the O2 pressure returns to equilibrium, the resulting films show a decrease in transition temperature with an expanded c-lattice parameter caused by defects in the non-chain sites of YBa2Cu3O7-δ. This demonstrates that a sufficiently high concentration of oxygen is needed during the time period that the fragments travel and deposit on the substrate.