Novel configurations for the fabrication of high quality REBCO bulk superconductors by a modified RE + 011 top-seeded infiltration and growth process

Abstract

Single domain REBCO bulk superconductors can be fabricated by the top-seeded infiltration and growth (TSIG) process, but there are some problems with removing the residual liquid phase from the bulks after crystal growth. The superconducting bulks fabricated by the TSIG process are generally obtained by slicing or polishing the REBCO bulks, which may produce cracks in the samples. In order to solve these problems, we proposed two novel configurations to prevent the REBCO bulks fusing together with the residual liquid phase by introducing transport layers or bars between the solid phase pellets and the liquid phase pellets. It is found that the REBCO bulks fabricated by the RE + 011 TSIG process can be easily separated from the residual liquid phase by using new configurations. We have also fabricated GdBCO bulks with 1 wt% CeO2 addition using the novel configuration. The CeO2 doping GdBCO bulk with diameter of 20 mm exhibits a very good trapped field of 1.110 T and levitation force of 54.5 N at 77 K. The results indicate that this is not only a good way to fabricate high quality single domain REBCO bulks, but also an important way to fabricate near net shape REBCO bulks without any mechanical process.