Melt-textured YBa2Cu3O7 − x wires having plate-like grains

Abstract YBCO wires which consist of well oriented plate-like fine grains are fabricated using a moving furnace to achieve higher mechanical strength. Melt-texturing experiments have been undertaken on YBCO wires with two different compositions: YBa 1.5 Cu 2.9 O 7− x , and YBa 1.8 Cu 3.0 O 7− x . Wires are extruded from a mixture of precursor powders (formed by a coprecipitation process) then textured by firing in a moving furnace. Size of secondary phases such as barium cuprate and copper oxide, and overall composition of the sample affect the orientation of the fine grains. At zero magnetic field, the YBa 1.5 Cu 2.9 O 7− x wire shows the highest critical current density of 1450 A cm −2 and 8770 A cm −2 at 77 K and 4.2 K, respectively. At 1 T, critical current densities of 30 A cm −2 and 200 A cm −2 , respectively, are obtained at 77 K and 4.2 K. Magnetisation curves are also obtained for one sample to evaluate critical current density using the Bean model. Analysis of the microstructure indicates that the starting composition of the green body significantly affects the achievement of grain alignment via melt-texturing processes.