物理化学学报 >> 1999, Vol. 15 >> Issue (01): 44-49.doi: 10.3866/PKU.WHXB19990109

研究论文 上一篇    下一篇

混合掺杂和非计量比对钕锶锰氧体系的影响

章建辉, 朱长飞, 李亚栋, 李晓光   

  1. 中国科学技术大学材料科学与工程系,合肥 230026|中国科学技术大学内耗与固体缺陷开放实验室,合肥 230026|中国科学技术大学化学系,合肥 230026
  • 收稿日期:1998-03-09 修回日期:1998-07-20 发布日期:1999-01-15
  • 通讯作者: 章建辉

Mixed Doping and Nonstoichiometry Effect in Manganate

Zhang Jian-Hui, Zhu Chang-Fei, Li Ya-Dong, Li Xiao-Guang   

  1. Department on Materials Science and Engineering,University of Science and Technology of China,Hefei 230026|Laboratory of Institute Friction and Defects in Solid Academia Sinica,University of Science and Technology of China,Hefei 230026|Department of Chemistry,University of Science and Technology of China,Hefei 230026
  • Received:1998-03-09 Revised:1998-07-20 Published:1999-01-15
  • Contact: Zhang Jian-Hui

摘要:

通过对Sr、Ba混合掺杂体系(x=0.27、0.165、0.06)和非计量体系Nd0.67SrxBaxMnOz(x=0.27,0.06),导电性能的研究发现:混合二价离子掺杂体系Nd0.67SrxBa0.33-xMnO3与单一二价离子掺杂体系(Nd0.67Sr0.33MnO3和Nd0.67Ba0.33MnO3)具有不同的导电机制,非计量比使Nd0.67SrxBaxMnOz体系出现晶格收缩,电阻率随温度的降低出现半导体-金属转变,与此同时体系的电阻率减小,另外还发现,Mn离子的非计量与A位离子的相比对体系晶格收缩和导电性能的影响都更为显著.

关键词: 混合掺杂, 非计量, 晶格收缩, 导电性

Abstract:

The microstructure and electric conduction variations in compounds Nd0.67Sr0.33-xBaxMnO3(x=0.27, 0.165, 0.06) and Nd0.67SrxBaxMnOz(x=0.27, 0.06) were studied. It was found that the conduction mechanism of Nd0.67Srx.Ba0.33-xMnO3 doped by mixed divalent ions differs from that of Nd0.67Sr0.33 MnO3 or Nd0.67Ba0.33MnO3 doped by single divalent ions. Due to the lattice contraction induced by nonstoichimetry, the resistivity reduces obviously and the resistivity transition (I-M) appears with decreasing temperature in Nd0.67SrxBaxMnOz. In addition, it was found that the lattice contraction induced by the nonstoichiometry on Mn site is larger than that on A site.

Key words: Mixed doping, Nonstoichiometry, Lattice contraction, Electric conduction