摘要
采用固相反应法制备了Nd0.5Sr0.5Co1–xMnxO3多晶样品(0≤x≤1)。利用X射线衍射仪和Rietveld方法精修程序分析了样品的晶体结构;对样品的磁性和电输运性能进行了测量。结果表明:样品均为斜方晶系单相结构,空间群为Imma。样品的晶格常数a、b、c,晶格平均扭曲率D和有效磁矩μeff随着Mn含量x的增加而增大,促使Co离子向高自旋态转变。在x≥0.6时,样品中Co离子都处于高自旋态。在样品中,Mn替代了Co,Mn—O—Co的反铁磁性超交换作用与Co3+—O2–—Co4+的铁磁性双交换作用相互竞争破坏了样品的金属导电行为,致使当x≥0.2时,样品表现出半导体导电行为。
Nd0.5Sr0.5Co1–xMnxO3（0≤x≤1） polycrystal were prepared by the solid state reaction method.The crystal structure of obtained samples was studied with XRD and Rietveld refinement program.The magnetic and electro transport properties of obtained samples were also investigated.The results show that all the samples exhibit single-phase orthorhombic structure（Imma）.The lattice constants a,b,c,average ratio of crystal lattice distortion D and effective magnetic moment μeff of samples increase with increasing Mn content,promoting Co ions transforming into high-spin state.All the Co ions are in high-spin state when x≥0.6.In the Nd0.5Sr0.5Co1–xMnxO3 samples,Co is substituted by Mn,and the antiferromagnetic super-exchange interaction of Mn—O—Co competes with the ferromagnetic double-exchange interaction of Co3＋—O2–—Co4＋,resulting in the worsening of metallic behavior of samples.The samples exhibit semiconductor behavior when x≥0.2.
出处
《电子元件与材料》
CAS
CSCD
北大核心
2010年第3期15-19,共5页
Electronic Components And Materials
基金
科技部重大科学研究计划资助项目(No2007CB925003)
