Transport properties of Si+ irradiated YBa2Cu3Oy thin films

Hall coefficients, magnetic hysteretic loops, and electrical resistivities in magnetic fields for YBa2Cu3Oy (YBCO) films under irradiation with Si+ were systematically examined in various ranges of temperature to investigate effects of the pinning force and disorder on the transverse Hall voltage near Tc. The incident energy of Si ions was 3 MeV and the fluence φt varied from 1 x 1012 to 1 x 1014 cm-2. Under irradiation with Si+, the critical current density of irradiated YBCO films derived from M-H curves showed enhancement and the resistive transition in magnetic fields became narrower in Si -irradiated YBCO films. The temperature ranges in which negative Hall coefficients occurred became narrower for a Si+-irradiated YBCO film that showed a stronger pinning force in magnetic fields; hence the negative Hall coefficient is affected by the pinning ability of YBCO films. The results are discussed