Studies On The Properties And Phase Formation Of Cu, C Doped MgB₂ Superconducter

Since the discovery of high Tc from MgB2, have been scientists from various countries have launched a lot of research. MgB2 superconductor by study on structural performance, a deeper level and broader perspective to observe the phenomenon of superconductivity of MgB2. explore its superconducting mechanism. MgB2 superconductor from the application point of view, On the one hand, MgB2 crystal structure is simple and easy to process and produce. On the other hand, the raw material for synthesis of MgB2:magnesium and boron-rich, low cost. In addition, MgB2 high critical magnetic field, critical current density characteristics of MgB2 superconductors have shown a very attractive potential applications. Currently, MgB2 superconductors for a lot of research, but the MgB2 system of many deficiencies. First of all, no systematic study of MgB2 phase formation thermodynamics and kinetics; Second, there is no systematic theory guiding doped phase-change process to achieve the optimization process, leading to preparation of MgB2 difficult to industrialization affect the process of its practical application. This study aimed at the above problems, Of Mg-B system characteristics and doping effect of chemical reaction, Powder by in situ synthesis of MgB2 superconducting wire casing, MgB2 superconducting techno-logy for the utility to provide the theoretical and experimental basis.Paper briefly introduces the history and development of superconductor research progress, It also introduces the basics of the superconductor and the basic concepts, Shows the object of this paper-The crystal structure of magnesium diboride and the electronic chart and the recent research progress in, Then it explains the ideas and topics of this paper the main work. For the experimental study of the doping research for reference, to study the superconductor MgB2 and its doping crystal structure changes, superconducting critical temperature increase, transformation process changes.Based on the Mg1-xCuxB2 and MgB2-yCy superconducting powder XRD,SEM and DTA curve of figure analyzed, confirmed the theoretically deduced on doping. And found that some C and Cu into the MgB2 lattice, but most of the doping elements are attached to the grain boundaries. At the same time with increasing temperature, some Mg evaporation, and a small number of MgB2 decomposition MgB4 and Mg. As the reaction time is short, large temperature gradient, Mg had a chance to spread a small liquid crystal again. At 750℃, the amount of MgB2 generated at least up and impurities, other doping elements present in the grain boundary position to exist in the form of mixed-phase grain boundaries in MgB2 and improve the superconduc-tivity of MgB2.