论文部分内容阅读
采用X射线衍射仪,扫描电镜,超导量子干涉仪等仪器对纳米C和SiC掺杂的MgB2带材进行了表征,并采用标准四引线法对样品的临界电流进行了测试.实验表明,C和SiC掺杂在提高MgB2带材高场下的临界电流密度方面具有显著效果.在温度为4.2K、磁场大于9T条件下,C和SiC掺杂样品的临界电流密度与未掺杂样品相比均提高一个数量级以上.掺杂样品高磁场下良好的临界电流性能主要归因于C对B的替代所产生的晶格畸变、位错等缺陷和局部成分变化而导致的有效晶内钉扎作用.实验结果表明,SiC掺杂的MgB2带材之所以具有非常好的高场电流特性,和C掺杂的样品一样,C对B的替代起到十分关键的作用.
The nanocrystalline C and SiC doped MgB2 ribbons were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and superconducting quantum interference (QCM) instrument.The critical current of the sample was tested by the standard four- And SiC doping have significant effects on increasing the critical current density in the high field of MgB2 tapes.The critical current densities of C and SiC-doped samples are lower than that of undoped samples at 4.2 K and more than 9 T All increased more than one order of magnitude.The good critical current performance under high magnetic field of doped samples was mainly attributed to the effective intra-crystal pinning effect caused by the defects of lattice distortion, dislocation and other local components caused by the substitution of C to B, The experimental results show that the reason why SiC doped MgB2 strip has very good high field current characteristics is that C plays a key role in the substitution of B just like C doped samples.