Structure of laser-modified YBa2Cu3O7−x thin films

High-Tc YBa2Cu3O7−x c-axis oriented thin films deposited by laser ablation were irradiated in-situ at their growth temperature by ultraviolet excimer-laser pulses with a fluence of up to 105 mJ/cm2. The resulting microstructure changes were investigated using X-ray diffraction and optical microscopy. Although the irradiation procedure leads to much smoother film surfaces, it also introduces a remarkable misorientation of YBaCuO grains creating a polycrystalline layer close to the top surface. [Copyright &y& Elsevier]