镁扩散制备Pr6O11掺杂的 MgB2块体临界电流密度和磁场性能研究

采用镁扩散方法制备了Pr₆O₁₁纳米颗粒添加的MgB₂超导块体,研究了Pr₆O₁₁掺杂对其临界电流密度(J_c),不可逆磁场(H_irr)和上临界磁场(H_c2)的影响。实验结果表明Pr₆O₁₁纳米颗粒掺杂明显提高了块体的J_c,H_irr和H_c2,但没有降低其超导转变温度T_c。在20 K自场条件下,质量比为1 wt.% Pr₆O₁₁掺杂的MgB₂块体的J_c较没掺杂样品提高了将近5倍, J_c=3.61×10₅A/cm₂。在10 K温度下,MgB₂块体H_c2 和H_irr较没掺杂样品分别提高了1.9 T and 2.6 T。同时讨论了Pr₆O₁₁纳米颗粒掺杂对MgB₂块体的电性能和磁通钉扎机制的影响。

Improved critical current density and magnetic properties of Pr6O11-doped MgB2 bulks synthesized by Mg-diffusion method

The effects of the addition of Pr₆O₁₁ nanopowder on the critical current density (J_c), irreversibility field (H_irr) and upper critical field (H_c2) of the MgB₂ bulks prepared by a Mg-diffusion method were investigated. The experimental results showed that J_c, H_irr and H_c2 of the MgB₂ bulks have been enhanced systematically by Pr₆O₁₁ nanopowder doping, but the superconducting transition temperature (T_c) was little affected. At 20 K in a self-field, the J_c value for the 1 wt.% Pr₆O₁₁-doped MgB₂ sample was 3.61×10₅A/cm₂, which was nearly five times larger than the undoped sample. In addition, at 10 K, the H_c2 and H_irr of the bulk increased by 1.9 T and 2.6 T, respectively. The Pr₆O₁₁-dopingmechanism on superconductivity and flux pinning was also discussed.