MICROSTRUCTURE OF OUTGROWTHS ON THE SURFACE OF LASER-ABLATED YBA2CU3O7 THIN-FILMS

The microstructure of the outgrowths on the surface of pulsed laser ab lated YBa2Cu3O7 (YBCO) thin films deposited on (100) Y stabilized zirc onia substrates was studied by transmission electron microscopy. The o utgrowths consist of misaligned superconducting c-axis YBCO grains and a-axis YBCO grains, non-superconducting CuO, Ba2CuO3, BaCuO2, CuYO2 a nd Y2BaCuO5 grains about 0.1-5 mum in size. The Y-123 type outgrowths are block-shaped misaligned with the YBCO matrix. The non-superconduct ing grains mostly are semi-spherical in shape and have a certain cryst allographic relation with the YBCO matrix. The protruding heights of t he outgrowths on the surface of the film are about 50-450 nm.