MgO粒子掺杂对NdBCO超导块材熔化温度的影响

采用改进后的顶部籽晶熔渗生长(RE+011 TSIG)工艺，通过在固相先驱粉中掺杂不同含量的MgO来有效地提高NdBCO籽晶的熔化温度，从而成功地制备出直径为32 mm的大尺寸单畴SmBCO超导块材.结果表明，MgO的掺杂对NdBCO超导块材的熔化温度有着明显的提高，随着固相先驱粉中MgO掺杂量的增加，Mg²⁺离子逐渐进入到Nd123相的晶格中，当掺杂量达到16 wt%时呈现出饱和状态，且NdBCO超导块材的熔化温度提高近18℃,可有效地抑制在制备SmBCO超导块材的过程中出现的NdBCO籽晶熔化现象.

Influence of MgO Particle Doping on Melting Temperature of NdBCO Bulk Superconductor

Compared with single domain YBCO and GdBCO bulk superconductors 9 SmBCO has attracted much attention due to its unique peak effect and superior superconductivity. However, it is difficult to prepare high performance and large | size single domain SmBCO bulk supercondcutors, because its high peritectic reaction temperature and Sm/Ba substitution effect, which seriously restrict the further development of large-size single?domain SmBCO bulk superconductors. Hence, in this paper, large single domain SmBCO bulk superconductor with diameter of 32 mm was successfully prepared with the Mg-NdBCO seeds fabricated in house by using the modified top-seed infiltration growth (RE+011 TSIG) process. The melting temperature of NdBCO seed crystals was effectively increased by doping different amounts of Mg() in the solid precursor powder. The results show that the melting temperature of NdBCO bulk superconductor is significantly increased by MgO doping. With the increase of MgO doping amount in the solid phase precursor powder, Mg2+ ions gradually enter to the lattice of Ndl23 phase. When the doping amount reaches 16 wt%, it presents a saturation state. The NdBCO seed crystal melting phenomenon in the process of preparing SmBCO bulk superconductor can be effectively suppressed. Therefore, a practical method for preparing high performance (RE)BCO bulk superconductor can be developed by using the Mg-NdBCO seed crystal with TSIG method, which provides an important basis for preparing large size SmBCO samples.