Critical current density of 165 kA/cm(2) at 4 K in bulk Bi2212/MgO textured by solidification in a high magnetic field and hot forging

Bulk Bi2212 superconductors with MgO addition are highly textured by solidi fication in a high magnetic field. Hot forging following this first step im proves the texture degree and enhances the critical current density. Critic al current density J(c),determined by transport and magnetic measurements f or temperatures between 77 and 4 K are presented. Transport J(c) reaches 19 00 A/cm(2) at 77 K in self-field, 4600 A/cm(2) at 65 K and 9500 A/cm(2) at 40 K. At 4 K, a J(c) of 165 kA/cm(2) is deduced from magnetization measurem ents. This value is comparable with those of multifilamentary Bi2212 conduc tors. An increase of the irreversibility line induced by hot forging after magnetic melt processing is also observed. (C) 1999 Elsevier Science B.V. A ll rights reserved.