CHARACTERISTICS OF BICRYSTAL-TYPE JOSEPHSON-JUNCTIONS OF YBA2(CU1-XNIX)(3)O-7-DELTA FILMS

We report the successful fabrication and characterization of the bicry stal-type Josephson junctions of YBa2(Cu1-xNix)(3)O-7-delta epitaxial thin films. Both T-c and I(c)R(n) products decrease with doping Ni, wh ile the ratio, d(T-c)/d(I(c)R(n)), is almost constant. The normal resi stance of the junction (R(n)) increases with resistivity in the normal state (rho(c)) of the electrode material. R(n)(5 K) for x approximate to 10% is similar to 9 times as high as that for x = 0%, while rho(n) (250 K) for x = 10% is similar to 3.8 times as high as that for x = 0% . The correspondent relation between R(n) and rho(n) indicates that th e barrier layer at the grain boundary consists of the same system as e lectrode superconductor. The increase of R(n) is explained by the decr ease of carrier mobility.