化学合成制备FeSe_(0.93)超导体的研究  

FeSe_(0.93) Superconductor Prepared by Chemical Synthesis Method

作　　者：柴青林[1] 屈飞[1] 李弢[1] 王磊[1] 华志强[1] 

机构地区：[1]北京有色金属研究总院超导材料研究中心,北京100088

出　　处：《稀有金属》2011年第5期700-703,共4页Chinese Journal of Rare Metals

基　　金：国家重点基础研究计划(973计划)(2011CBA00105)资助项目

摘　　要：采用有机合成的方法制备配位化合物FeSe2粉末,然后将该前驱粉末在650℃下真空环境退火得到β-FeSe0.93粉末,经烧结最终制得具有超导性能的FeSe0.93体材料。采用扫描电镜、X射线衍射及能谱仪对两种粉末进行了成分和形貌分析,结果表明,化学合成得到的FeSe2粉末颗粒呈八面体状,粒度均匀,尺寸约0.5μm。而FeSe2粉末经高温退火后发生分解,铁硒比随着硒单质的逸出而增大,最终获得粉末成分为FeSe0.93,颗粒发生融合使得粒度增大,由于分解反应的无序性使得产物中有少量的非超导相(α-FeSex)。粉末经压制成锭后750℃下烧结,对FeSe0.93粉末制块材进行了超低温下电输运测量的研究,多物性测量系统(PPMS)测试结果表明该体材料初始超导转变温度(Tc,onset)约为11 K,同时存在零电阻特性(Tc,0=4 K),超导性能得到较好的表现。因为非超导的杂相存在对铁硒化学计量比产生微扰,没能获得更好的输运测量结果。An organic synthesis method was used to prepare the coordination compound precursor-FeSe2 powders. β-FeSe0.93 powders were obtained by annealing the prepared precursor in a vacuum environment at 650℃ and superconducting FeSe0.93 bulk was prepared after sinter/ng ultimately. The composition and morphology of the two kinds of powders were characterized with scanning electron microscopy, X-ray diffraction and energy dispersive spectrometer. The results showed that the uniform size of octahedral FeSe2 powders synthesized by chemical method was about 0. 5μm. FeSe2 powders decomposed in the process of high temperature annealing, and the ratio of Fe/Se increased withthe selenium escape. The final composition was FeSe0.93. The grains got fusion led to the increase of grain size, and a small amount of non-superconducting α-FeSex appeared for the disorder of decomposition reaction. The ingot pressed by powders sintered at 750℃. The obtained bulk was researched by ultra-low temperature transport measurement. The result of physical property measurement system showed that Tc.onset , was about 11 K, and the zero-resistance feature occurred at 4 K. The superconducting properties got well performance. But because non-superconducting impurity generated perturbation to the stoichiometry of FeSe,, the transport measurement result did not present much better.

关 键 词：有机合成 FESE 超导体 

分 类 号：TB34[一般工业技术—材料科学与工程]