C和SiC掺杂对分步反应法制备MgB_2块体和线材微观结构的影响（英文）  

Effect of Carbon and Si C Doping on Microstructures of MgB_2 Bulks and Wires by a Two-Step Reaction Method

作　　者：杨芳[1] 王庆阳[1] 熊晓梅[1] 刘国庆[1] 闫果[2] 冯建情[1] 李成山[1] 

机构地区：[1]西北有色金属研究院,陕西西安710016 [2]西部超导材料科技股份有限公司,陕西西安710018

出　　处：《稀有金属材料与工程》2016年第1期75-78,共4页Rare Metal Materials and Engineering

基　　金：National Basic Research Program of China("973"Program)(2011CBA00104);The National High Technology Research and Development Program of China("863"Program)(2014AA032701);National Natural Science Foundation of China(51302226,51372207)

摘　　要：通过两步反应法制备了C和SiC掺杂的MgB_2块材和线材。首先,按一定比例均匀混合Mg粉、B粉和C或SiC粉,压块后在900℃密闭氩气条件下烧结2 h,得到C或SiC掺杂的MgB 4块体;将一次烧结后的MgB_4块体磨碎过筛,和补充的Mg粉混合作为前驱粉末制备MgB_2,MgB_2块体在密闭氩气条件下750℃烧结2 h而MgB_2线材在密闭氩气条件下680℃烧结2 h。同时采用传统的固态烧结法制备了C或SiC掺杂的Mg B2块体以作对比。对烧结后的样品进行了微观结构和相组成等分析检测。分步反应法与以往的固态烧结法相比,不仅因降低了Mg元素的影响而提高样品组织致密性,更因其采用了分步混合粉末而大大地提高了元素掺杂的均匀性。和SiC掺杂相比,C掺杂能更有效地进入MgB_2晶粒和晶界。Carbon and Si C doped MgB2 bulks and wires were fabricated by a two-step reaction method. The MgB4 samples were sintered at 900 °C for 2 h in closed argon atmosphere, and then an appropriate amount of Mg powder was mixed with the ground MgB4 powder to get Mg B2 green compacts, which were sintered at 750 °C for 2 h to get bulk samples or at 680 °C for 2 h to get wire samples in closed argon atmosphere. Carbon or SiC doped MgB2 bulk samples were also prepared by conventional solid state sintering for comparison. The phase evolution and the microstructure of MgB2 samples were characterized by means of X-ray diffraction（XRD） and scanning electron microscope（SEM）. The SEM results indicate that the compactedness and the dopant distribution homogeneity of MgB2 samples prepared by the two-step reaction method are improved obviously. The carbon doping can more effectively introduce the dopants into MgB2 crystalline lattice and grain boundaries compared with SiC doping.

关 键 词：MGB2 掺杂 相转化 烧结 两步反应 

分 类 号：TQ132.2[化学工程—无机化工]