Cu/Y_2O_3掺杂MgB_2的组织控制及动力学分析  

Microstructure and kinetics of Cu/Y_2O_3-doped MgB_2

作　　者：蔡奇[1] 刘永长[1] 马宗青[1] 高志明[1] 余黎明[1] 

机构地区：[1]天津大学材料科学与工程学院天津市材料复合与功能化重点实验室,天津300072

出　　处：《材料热处理学报》2012年第9期7-12,共6页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51077099);教育部新世纪优秀人才资助计划(NCET-05-0250)

摘　　要：观察并研究了不同Y2O3含量的Cu/Y2O3共掺杂MgB2的体系,样品通过传统的固相烧结法制备。结合扫描电镜和X射线衍射技术的分析发现,只有在5%Y2O3掺杂的样品中获得了层状组织。选择5%Y2O3含量的体系结合热分析曲线对固相反应阶段进行了动力学分析,得出最概然机理函数为Avrami-Erofeev,n=2,表达式为2[-ln(1-α)]1/2。其意义是随机形核和随后的瞬时生长。最后对动力学参数进行了计算,结果表明反应的活化能和指前因子均先趋于稳定后减小。Cu/Y2O3-doped MgB2 samples with different Y2O3 content were prepared by traditional solid-state sintering method.The microstructure and phase composition of the material were analyzed by SEM and X-ray diffraction.The results show that layered structure only appeares in Cu/5%Y2O3-doped sample.The solid-solid reaction of this system is further investigated by kinetics analysis in terms of thermal analysis curves.Finally,the most appropriate mechanism function is ascertained to be Avrami-Erofeev,n=2,which means random nucleation followed by instantaneous growth of nuclei.The activation energy(E) and the pre-exponential factor(A) both trend to be stable at early stage and decrease at final stage.

关 键 词：MGB2超导体 显微组织 动力学 

分 类 号：TG132.26[一般工业技术—材料科学与工程]