No abstract

No abstract

A two-step process is proposed for the formation of c-axis aligned (Bi,Pb)2Sr2Ca2Cu3O10+δ  [Bi(2:2:2:3)] platelets in a silver sheath. The process involves: (1) the formation of c-axis aligned (Bi,Pb)2Sr2CaCu2O8+δ  at early stage of heat treatment and (2) the subsequent intercalation of Ca–Cu–O layers to form Bi(2:2:2:3). This is based on the measurements of (1) the rocking curves for c-axis alignment and the two theta scans for the Bi(2:2:2:3) conversion ratio, both by a transmission x-ray technique, and (2) a quantitative study of the phase conversion due to intercalation of Ca–Cu–O layers into existing Bi(2:2:1:2) by transmission electron microscopy.

No abstract

No abstract

The angular distributions of large-angle grain boundaries were studied by electron microscopy for Bi(2:2:1:2) and Bi(2:2:2:3) composite tapes. For Bi(2:2:2:3) the distributions are random, while for Bi(2:2:1:2), there was a high incidence of special boundary misorientations. The preferred orientations in Bi(2:2:1:2), which were analyzed for [001] and [100] rotations, agreed well with the calculated lattice coincidences based on the constraint Coincidence Site Lattice model, and were attributed to the reorientation of the neighboring grains during its partial melt process.