(Hg,M)-1222相铜氧化合物的合成及其超导电性研究(M=W、Mo、Ti、V、Cr)  

THE SYNTHESIS AND SUPERCONDUCTIVITY OF (Hg,M)-1222 PHASE COPPER OXIDE (M=W, Mo, Ti, V, Cr)

作　　者：刘路[1] 李世燕[1] 樊荣 陈仙辉[1] 

机构地区：[1]中国科技大学结构分析开放实验室和物理系,合肥230026

出　　处：《低温物理学报》2000年第5期358-362,共5页Low Temperature Physical Letters

摘　　要：分别用固相反应和柠檬酸盐溶胶 凝胶法制备名义组成为Sr2 (Gd1 .5Ce0 .5)Cu2 Oz 的前驱物 ,再用真空烧结的方法合成了 (Hg ,M) 12 2 2相铜氧化合物 (Hg0 .75 M0 .2 5)Sr2 (Gd1 .5Ce0 .5)Cu2 Oz(M =W ,Mo ,V ,Cr,Ti) .溶胶 凝胶法同固相法相比混合更均匀 ,反应温度低 ,成相情况好 .改进该方法后 ,用溶解度较高的Ce(NO3) 3代替不溶于硝酸的CeO2 ,制得了纯 12 2 2相 .研究了不同退火条件对样品电阻温度特性的影响 ,发现高氧压退火有助于超导转变 .M =W ,Mo时得到超导体 ,Tc(onset) 在 13～ 2The precursor, which was prepared by solid state reaction and the citrate sol gel process, was sintered in vacuum to synthesize Hg 1222 with nominal compositions (Hg\-\{0.75\} M \-\{0.25\})Sr\-2(Gd\-\{1.5\}Ce\-\{0.5\})Cu\-2O\- z ( M =W, Mo, V, Cr, Ti). The sol gel process showed advantage in mixing the reagent more homogeneous, sintering at rather low temperature and obtaining better 1222 phase. We improved such method by replacing the unsolvable CeO\-2 with diffluent Ce(NO\-3)\-3 and successfully synthesized pure 1222 phase. Superconductivity was improved when annealed at high pressure of O\-2. The samples doped with W and Mo show superconductivity with T\-c of 13～27K.

关 键 词：汞系 超导体 铜氧化合物 超导电性 

分 类 号：O511[理学—低温物理] TM262[理学—物理]