Enhancement of the critical current density and flux pinning of MgB2 superconductor by nanoparticle SIC doping
Enhancement of the critical current density and flux pinning of MgB2 superconductor by nanoparticle SIC doping
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DOI：
10.1063/1.1517398
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发表时间：
2002-10-28
影响因子：
4
通讯作者：
Tomsic, M
中科院分区：
文献类型：
--
作者：
Dou, SX;Soltanian, S;Tomsic, M
研究了纳米SiC对MgB_2的掺杂及其改善磁通钉扎的潜力，并对MgB_2-x（SiC）（x/2）（x=0，0.2和0.3）和掺杂10wt%纳米SiC的MgB_2样品进行了研究。用Si和C共取代B抵消了单元素掺杂的影响，使Tc仅降低1.5 K，引入了在高场和温度下有效的晶粒内钉扎中心，并显著提高了J（c）和H-irr。与未掺杂的样品相比，10wt%掺杂的样品的J（c）在5 K和8 T下增加了32倍，在20 K和5 T下增加了42倍，在30 K和2 T下增加了14倍。在20 K和2 T下，掺杂样品的J（c）为2.4 × 10（5）A/cm（2），这与最佳Ag/Bi-2223带材的J（c）值相当。在20 K和4 T下，J（c）是最好的MgB 2薄膜的两倍，并且比最好的Fe/MgB 2带高一个数量级。磁场J（c）是一致的。在10 T和5 K下，掺杂样品的输运J（c）仍保持在20000 A/cm（2），比未掺杂样品高一个数量级。由于这种高性能，预计未来的MgB 2导体将使用MgBxSiyCz的配方而不是纯MgB 2制成。(C)2002年美国物理学会。
Doping of MgB2 by nano-SiC and its potential for the improvement of flux pinning were studied for MgB2-x(SiC)(x/2) with x=0, 0.2, and 0.3 and for 10 wt% nano-SiC-doped MgB2 samples. Cosubstitution of B by Si and C counterbalanced the effects of single-element doping, decreasing T-c by only 1.5 K, introducing intragrain pinning centers effective at high fields and temperatures, and significantly enhancing J(c) and H-irr. Compared to the undoped sample, J(c) for the 10 wt% doped sample increased by a factor of 32 at 5 K and 8 T, 42 at 20 K and 5 T, and 14 at 30 K and 2 T. At 20 K and 2 T, the J(c) for the doped sample was 2.4x10(5) A/cm(2), which is comparable to J(c) values for the best Ag/Bi-2223 tapes. At 20 K and 4 T, J(c) was twice as high as for the best MgB2 thin films and an order of magnitude higher than for the best Fe/MgB2 tapes. The magnetic J(c) is consistent. with the transport J(c) which remains at 20000 A/cm(2) even at 10 T and 5 K for the doped sample, an order of magnitude higher than the undoped one. Because of such high performance, it is anticipated that the future MgB2 conductors will be made using a formula of MgBxSiyCz instead of pure MgB2. (C) 2002 American Institute of Physics.