纳米镁粉在制备理论密度MgB_2样品中的作用  

The effect of nanometer Mg powder on preparing theoretical density MgB_2 sample

作　　者：冯庆荣[1] 陈晋平[1] 李星国[2] 靳长青 

机构地区：[1]北京大学物理系,北京100871 [2]北京大学化学系,北京100871 [3]中国科学院物理所,北京100080

出　　处：《云南大学学报（自然科学版）》2005年第S1期93-96,100,共5页Journal of Yunnan University(Natural Sciences Edition)

基　　金：国家重点基金研究项目(BKBRSF-G19990646-02)

摘　　要：纳米镁粉通过高温高压法用于制备MgB2块材样品,得到了含有少量MgO杂相的密度为2.67g/cm3的理论密度MgB2超导样品.扣除MgO的影响。可以得到MgB2块材样品的密度是2.54g/cm3.样品SEM照片表明样品的晶粒间没有空隙.这是保证其密度能达到理论密度值的主要原因.M-T和R-T测量表明样品的超导转变温度Tc=39K,零场下4.2K的磁临界电流密度Jc=3×105A/cm2;下临界磁场Hc1=63662.4A/m,较普通颗粒镁粉和硼粉在各种条件下制得的MgB2样品的Hd值都要高.The theoretical density MgB2 sample was prepared by using nanometer Mg powder (the grain size is about 80 nm) and micrometer B powder (the grain size is 1μm) as the raw materials under 5.5 GPa at 850℃ for 1 hour. There were little amount MgO impurity phase in this sample. After taking off the influence of MgO on the sample density, it was obtained the density of pure MgB2 is 2.56 g/cm3. It is nearly the theoretical density value of MgB2. The SEM images indicated that there is not any hole or cave in the sam...

关 键 词：纳米镁粉 MGB2 X射线衍射 SEM图 

分 类 号：TB383[一般工业技术—材料科学与工程]