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MgB2超导体具有临界转变温度39K、原材料廉价及制备工艺简单等优点,被认为是MRI中已用超导体最好的替代者.但是临界电流密度(Jc)随外加磁场增大下降较快的这一问题极大的阻碍了其实际中的应用.实验结果表明:采取掺杂的方法来提高MgB2的超导电性尤其是高场下Jc值是一条有效的途径.本文概述了用单质碳和含碳化合物对MgB2超导体进行掺杂从而提高其超导特性的最新研究工作,具体介绍了掺杂物颗粒大小、掺杂量以及烧结温度等参数对MgB2超导电性的影响.研究表明:在碳单质掺杂中纳米级碳颗粒和碳纳米管具有比较好的掺杂性能,可以大幅度提高高场下的Jc值;在含碳化合物中,用纳米级SiC进行掺杂不仅可以大幅度提高高场下的Jc值,而且相比碳单质有更高的Tc值.根据目前的研究结果,最后本文对MgB2超导体掺杂研究的未来发展趋势进行了展望.
MgB2 superconductors have the critical transition temperature of 39K, low cost of raw materials and simple preparation process, which is considered as the best substitute for superconductor used in MRI. However, the critical current density (Jc) decreases rapidly with the increase of applied magnetic field Which greatly hindered its practical application.The experimental results show that it is an effective way to improve the superconductivity of MgB2, especially Jc at high field by adopting the doping method.In this paper, MgB2 superconductors doped to improve the superconducting properties of the latest research work, the specific introduction of the dopant particle size, doping amount and sintering temperature and other parameters on the superconductivity of MgB2 superconductivity.The results show that: in the carbon elemental doping Nano-scale carbon particles and carbon nanotubes have better doping properties, can greatly improve the Jc under high field; in carbon-containing compounds, with nano-SiC doping can not only greatly improve the high field Jc value, but also higher Tc than the carbon element.According to the results of the present study, the future of the MgB2 superconductor doping research prospects for the future development trend.