“…Ivanov and co-workers revealed that in addition to the misorientation angle , the orientation of the main crystal axes with respect to the grain boundary has a decisive influence on the critical current density (Ivanov et al, 1998). Experiments with ϭ32°[001]-tilt boundaries performed at 4.2 K displayed a reduction of J c by a 5 These superconductors include doped La 2 CuO 4 (Kawasaki et al, 1993;Beck et al, 1996), Ag-doped YBa 2 Cu 3 O 7Ϫ␦ (Holzapfel et al, 2000), NdBa 2 Cu 3 O 7Ϫ␦ (Romans et al, 2001), Bi 2 Sr 2 CaCu 2 O 8ϩ␦ (Tomita et al, 1990;Mayer et al, 1993;Amrein et al, 1995;, Bi 2 Sr 2 Ca 2 Cu 3 O 10ϩ␦ (Ohbayashi et al, 1995;Yan et al, 1995;Frey et al, 1996b;Takami et al, 1996;Yoshida et al, 1997;Attenberger et al, 2001), Tl 2 Ba 2 CaCu 2 O 8ϩx (Cardona et al, 1993;Sarnelli et al, 1994;Y. F. Chen et al, 1996;Weaver et al, 1996), Tl 1 Ba 2 Ca 2 Cu 3 O x (Nabatame et al, 1994), HgBa 2 CaCu 2 O 6ϩ␦ (Gupta et al, 1994;Tsukamoto et al, 1998;Yu et al, 1999;Inoue et al, 2000;Adachi et al, 2001), and Nd 2Ϫx Ce x CuO 4 (Kawasaki et al, 1993;Kussmaul, Tedrow, and Gupta, 1993;Kleefisch et al, 1998;Schoop et al, 1999;Woods et al, 1999).…”