C-axis oriented YBa2Cu3O7-x (YBCO) thin films were deposited on polycrystalline metallic tapes buffered with yttria stabilized zirconia (YSZ). The in-plane alignment of the YSZ layers achieved by simultaneous ion bombardment of the growing film (ion beam assisted deposition) and of the postdeposited YBCO thin films was studied by x-ray diffraction as a function of the buffer layer thickness. A significant improvement of the in-plane texture, achieved for buffer layers exceeding a thickness of about 1.5 mu m, resulted in high critical current densities above 10(6) A/cm(2) of the YBCO films. (C) 1997 American Institute of Physics.