采用原位法粉末装管工艺( in-situ PIT)制备了无定形碳掺杂MgB2/Nb/Cu超导线材并研究了该掺杂对MgB2微观结构及超导电性的影响.复合线材中以Nb作为阻隔层、Cu作为稳定体并采用冷拉拔工艺进行加工.研究了无定形碳掺杂对MgB2相形成、微观结构及超导电性的影响,其中掺杂量分别为MgB2-xCx(x=0.0,0.05,0.08,0.10,0.15).分别采用XRD、SQUID、SEM/EDS及传输电流测试等方法对MgB2/Nb/Cu线材进行分析测试.XRD分析结果显示,700℃热处理后的线材可以获得纯度较高的MgB2超导相;微观结果照片显示无定形碳掺杂后可以获得良好的晶粒连接性;能谱分析表明掺杂物C元素均匀的分布在MgB2基体中;通过四引线法测试了传输临界电流密度Jc,在4.2 K、5T,其Jc值高达1.4×105 A/cm2;在4.2K、10T,其Jc值为3.3×104A/cm2.
The effects of amorphous carbon doping on superconducting properties of MgB2/Nb/Cu wires fabricated by the in-situ powder-in-tube (PIT) method have been investigated.Using Nb as the barrier and Cu as the stabilizer,the MgB2 wires were fabricated by cold drawing.The wires of MgB2-xCx (x =0.0,0.05,0.08,0.10,0.15) have been investigated to realize the effect of amorphous carbon doping on the phase formation,microstructure and superconducting properties.Characterization of MgB2/Nb/Cu wires was carried out using XRD,SQUID,SEM/EDS,and Jc measurements.XRD result shows that the high purity MgB2 phase is acquired after heat-treatment at 700℃.The microstructure observation for wires shows that the MgB2/Nb/Cu wires have better grain connectivity after doping amorphous carbon,and Energy Dispersive X-ray (EDS)analysis confirms the uniform distribution of carbon in the MgB2 superconducting phase.The critical current density (Jc) of wires was measured in different magnetic fields by a standard four probes method,and the transport Jc values as high as 1.4 ×105 A/cm2 (4.2 K,5 T) and 3.3× 104 A/cm2 (4.2 K,10 T) have been achieved.
参考文献
| [1] | Nagamatsu J;Nakagawa N;Muranaka T;Zenitani Y;Akimitsu J .Superconductivity at 39 K in magnesium diboride[J].Nature,2001(6824):63-64. |
| [2] | Larbalestier DC;Cooley LD;Rikel MO;Polyanskii AA;Jiang J;Patnaik .Strongly linked current flow in polycrystalline forms of thesuperconductor MgB2[J].Nature,2001(6825):186-189. |
| [3] | Matsumoto A.;Kumakura H.;Kitaguchi H.;Hatakeyama H.;Yamada H.;Hirakawa M. .The microstructures and superconducting properties of MgB/sub 2/ tapes processed in-situ by a ball-milling method[J].IEEE Transactions on Applied Superconductivity: A Publication of the IEEE Superconductivity Committee,2005(2):3333-3336. |
| [4] | Dou S X;Yeoh W K;Shcherbakova O et al.[J].Applied Physics Letters,2006,89:202504. |
| [5] | Fang H;Alessandrini M;Wang X M et al.[J].IEEE Transactions on Applied Superconductivity,2009,19(03):3520. |
| [6] | Ojha N;Malik V K;Rashmi Singla et al.[J].Superconductor Science and Technology,2010,23:045005. |
| [7] | Cheng, C.H.;Yang, Y.;Ke, C.;Lin, H.T. .Iron doping effect on superconducting properties of MgB_2[J].Physica, C. Superconductivity and its applications,2010(20):1092-1095. |
| [8] | Zhang X P;Wang D L;Gao Z S et al.[J].Superconductor Science and Technology,2010,23:025024. |
| [9] | Lee, CM;Park, JH;Hwang, SM;Lim, JH;Joo, J;Kang, WN;Kim, CJ .Fabrication of ex situ processed MgB2 wires using nano carbon doped powder[J].Physica, C. Superconductivity and its applications,2009(15/20):1527-1530. |
| [10] | Lim J H;Kim K T;Park E C et al.[J].Phyica C,2008,468:1379. |
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