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。
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 studicd.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.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
1999年第1期44-49,共6页
Acta Physico-Chimica Sinica
基金
国家自然科学基金
关键词
混合掺杂
巨磁电阻材料
非计量比
稀土锰氧化物
Mixed doping, Nonstoichiometry, Lattice contraction, Electric conduction
