同质冷籽晶技术生长SmBCO/Ag超导单畴块材的研究

在前期的研究中,利用NdBCO123冷籽晶技术成功制备出具有理想织构的SmBCO/Ag单畴块材.但由于高质量的Nd籽晶的供应难以得到保证,从而限制了SmBCO单畴块材的批量化制备.Ag可以降低SmBCO坯体的熔点,这为用SmBCO冷籽晶技术引导SmBCO/Ag坯体生长单畴块材提供了可能性.然而,实验中我们发现,坯体里面的Ag容易向籽晶内部扩散,导致籽晶熔融,对单畴块材的生长产生不利影响.为克服这困难,我们通过在坯体和籽晶之间加入一个SmBCO211缓冲层,有效地阻止坯体里面的Ag向籽晶扩散,成功实现了同质冷籽晶技术生长SmBCO超导单畴块材.

STUDY ON THE GROWTH OF Ag-DOPED Sm-Ba-Cu-O BULK USING SMBCO COLD SEED

We have previously reported on the single domain growth of Ag-doped SmBCO bulk using NdBCO123 cold seed technique.However,it is difficult to get NdBCO123 seed,limiting the fabrication of SmBCO single domain.Because Ag can decrease the peritectic decompositon temperature,it is possible to growth Ag-doped SmBCO bulk with SmBCO cold seed.But in the experiment,we found Ag is easy to diffuse to the seed from the bulk precursor,resulting the seed melted and effcting the melt-growth of SmBCO single domian.In order to solve the problem,by inserting a buffer layer of SmBCO211 between the seed and bulk precursor,to prevent Ag spreading from bulk precursor to seed,we successfully textured SmBCO mono-domain crystals with 15mm on a side using SmBCO123 cold seeding technique.