The growth mechanism of air-processed c-oriented large grain Nd-Ba-Cu-O/Ag superconductor prepared with the hot-seeding technique was studied. We prepared NdBCO by adding 10-30 mol% Nd210 (or 25 wt% Nd422) and 0-10 wt% Ag. Small amounts of CeO2 have been added to refine the non-superconducting Nd422 inclusions. The melt-texture growth was performed in air with an Ag-free NdBCO seed at an elevated temperature. A c-oriented grain of 20 mm diameter has been obtained, which contained some sub-grains and residual liquid phase. It is found that the residual liquid phases lead to the disintegration of the Nd210-added bulks after melt-growth. The Nd422 size in Nd210-added samples was much smaller than that in Nd422-added samples. The results show that Tc may be depressed with the addition of Ag. However, after a high-temperature Ar heat treatment, the Tc and Jc (H, T) of the Ag-added samples reach 91 K and 2.0 × 104 A cm-2 at 77 K without external field. These values are higher than those of the Ag-free samples with Nd210 addition.
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Condensed Matter Physics
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry