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以无定形碳粉末作为掺杂物质,通过固相烧结的方法,在750℃,高纯氩气保护下,热处理2h制备了MgB2-xCx(x=0,0.05,0.10,0.20,0.30)超导块材。用X射线衍射(XRD)仪,扫描电子显微镜(SEM)和物性测试仪(PPMS)对样品的微观结构和超导电性进行了系统分析。结果显示,在750℃热处理条件下,有部分碳进入MgB2的晶格中,其余碳处于MgB2的晶界处。少量碳掺杂可以有效细化MgB2晶粒,并改善MgB2的超导电性。MgB1.9C0.1块材的临界电流密度(Jc)在20K,3T条件下达到8×104A/cm2,表明无定形碳掺杂可有效提高MgB2的磁通钉扎。
Using amorphous carbon powder as doping material, MgB2-xCx (x = 0,0.05,0.10,0.20,0.30) was prepared by solid-phase sintering at 750 ℃ under the protection of high purity argon for 2h Guide block material. The microstructure and superconductivity of the samples were systematically analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and physical property tester (PPMS). The results show that at 750 ℃ heat treatment conditions, some of the carbon into the lattice of MgB2, the rest of the carbon in the grain boundaries of MgB2. A small amount of carbon doping can effectively refine the MgB2 grains and improve the superconductivity of MgB2. The critical current density (Jc) of MgB1.9C0.1 block reaches 8 × 104A / cm2 at 20K and 3T, which indicates that amorphous carbon doping can effectively improve the flux pinning of MgB2.