Critical current of HoBa/sub 2/Cu/sub 3/O/sub y/ tape fabricated by inclined substrate deposition

HoBa/sub 2/Cu/sub 3/O/sub y/ (HoBCO) films on the bi-axially textured buffer layer prepared by Inclined Substrate Deposition method are studied. The HoBCO and buffer layers are supported by Ni-based-alloy substrate to form superconducting tape. Critical current density (J/sub c/) of this tape exceeds about 1/spl times/10/sup 9/ A/m/sup 2/ at 77 K in the self-field. To investigate practical performance of this tape, various dependences of J/sub c/, such as the magnetic-field dependence is measured. For the measurement of J/sub c/ in the magnetic field, its dependence of the angle of the field and the tape's plane is taken into account. The result shows that J/sub c/ has a notable peak when the magnetic field is perpendicular to the angle of the field to the tape's plane. The J/sub c/ peak gradually diminishes as the field increases. Similar magnetic field dependence of J/sub c/ is observed in a YBa/sub 2/Cu/sub 3/O/sub y/ (YBCO) sample. This study confirms that data of the perpendicular and parallel field dependence of J/sub c/, as such, are not sufficient for evaluation of practical performance of HoBCO tape.