化学学报 ›› 2003, Vol. 61 ›› Issue (11): 1844-1848. 上一篇    下一篇

研究论文

层状晶体β-MNCl(M=Zr,Hf)的电子掺杂新方法及其性质研究

朱丽萍;叶志镇   

  1. 浙江大学
  • 发布日期:2003-11-15

New Electron-doping Method for Layer-Structured Crystals of β-MNCl (M=Zr, Hf) and Their Properties

Zhu Liping;Ye Zhizhen   

  1. State Key Laboratory of Silicon Material, Zhejiang University
  • Published:2003-11-15

通过控制叠氮化物RN_3(R=Li, Na, K, Rb)与层状晶体β-MNCl (M = Zr, Hf) 反应的摩尔比,成功地对层状晶体β-MNCl(M=Zr, Hf)进行了电子掺杂,得到了转 变温度分别是13.5K和23.5K的超导体。实验结果还进一步表明,当摩尔比x=n (NaN_3)/n(β-ZrNCl)=0.3时,反应所得反插层化合物ZrNCl_(1-x)经450 ℃退火处 理后,其超导性质最好。作者同时利用XRD,TEM和SQUID测试结果,分析了化学反 应机理和电子掺杂原理,并研究了所得超导体在空气中的稳定性。

关键词: 叠氮化物, 掺杂, 超导体, 锂化合物, 钠化合物, 钾化合物, 铷化合物, 锆化合物, 铪化合物, X射线衍射分析

Layer-structured crystals of /?-MNCl (M = Zr, Hf) have been electron-doped successfully by reactions with alkali metal azides RN3 (R = Li, Na, K, Rb), the amounts of which were controlled with the molar ratios of azides to jfi-MNCl. The prepared compounds show superconductivity with transition temperatures ( Tm) at 13.5 K for /3- ZrNCl and 23.5 K for /3-HfNCl. The results of the experiments showed that the sample obtained from the reaction with the molar ratio of x = ?(NaN3)/ft(/?-ZrNCl) =0.3 was bulk superconductor. The mechanisms of reactions and electron-doping were studied tentatively by the results of XRD, TEM and SQUID measurements. The stability of the obtained superconductors in air was also investigated.

Key words: AZIDE, DOPE, SUPERCONDUCTORS, LITHIUM COMPOUNDS, SODIUM COMPOUNDS, POTASSIUM COMPOUNDS, RUBIDIUM COMPOUNDS, ZIRCONIUM COMPOUNDS, HAFNIUM COMPOUNDS, XRD