SPIRAL GROWTH IN PULSED-LASER DEPOSITED YBA2CU3O7-DELTA FILMS

Using Pulsed Laser Deposition, rye find that a high background pressur e favours tile formation of growth spirals on YBa2Cu3O7-delta thin fil ms. At these elevated pressures 2D-nucleation and growth can be induce d by putting the substrate well into the laser plume. We attribute thi s growth mode transition to a change in surface diffusivity. This conf irms the close relationship between plume dynamics and surface kinetic s in PLD.