零磁场下La_(0.67)Sr_(0.33-x)Na_xMnO_3的电输运特性研究  

STUDY OF ELECTRICAL TRANSPORT PROPERTIES FOR La_(0.67)Sr_(0.33-x)Na_xMnO_3 IN ZERO FIELD

作　　者：唐永刚[1] 彭振生[1,2] 王桂英[1] 郭焕银[1] 

机构地区：[1]宿州学院自旋电子与纳米材料安徽省重点实验室宿州学院,宿州234000 [2]中国科学技术大学结构分析重点实验室中国科技大学,合肥230026

出　　处：《低温物理学报》2009年第3期193-197,共5页Low Temperature Physical Letters

基　　金：国家自然科学基金重点项目(编号:19934003);安徽省教育厅自然科学研究重大项目(编号:ZD2007003-1);安徽省教育厅自然科学研究项目(编号:KJ2008A19ZC);宿州学院教授(博士)科研启动基金项目(编号:2006jb02)资助的课题~~

摘　　要：采用固相反应法制备了样品La0.67Sr0.33-xNaxMnO3(x=0.05,0.10,0.15,0.20,0.25,0.33).通过样品的红外吸收光谱、Ramam光谱、ρ～T曲线以及ρ～T拟合曲线,研究了样品的晶格结构变化和输运性质.结果表明:随Na掺杂的增加,Mn-O-Mn的键长、键角变化加大;体系属于双交换作用输运机制;在低温区(T<Tp),满足ρ～T2关系,输运机制是单磁子散射作用,而在高温区(T>Tp),用[ρ-Texp(T0/T)]拟合得很好,ρ(T)符合极化子近邻跃迁模型.A serial of samples of La0.67Sr0.33-xNaxMnO3（x=0.05,0.10,0.15,0.20,0.25,0.33）were synthesized by the standard solid-state reaction. The variation in crystal structure and the transport properties of the sample were investigated through FTIR spectrum, Raman spectrum,ρ～T curves and ρ～Tfitted curves. Our experiment shows that the variation in band length and band angle of Mn-O-Mn increases with increasing of Na content; the transport mechanism originates from double-exchange interaction; on the low temperature range（ T 〈 Tv ）,ρ（T） accords with the ρ-T2 relation, and the transport mechanism is the function of single magneton scattering, while on the high temperature range（ T 〉 Tp）, all of ρ T curves are fitted very well by [ρ-Texp（ T0/T） ] and p（T） accords with near-neighbor-hopping model of polaron.

关 键 词：Na掺杂 晶格结构 双交换作用 单磁子散射 极化子近邻跃迁 

分 类 号：O482.4[理学—固体物理]