La_(1/3)Sr_(2/3)Fe_(1-x)Co_xO_3体系中的Co替代效应研究  

THE STUDIES IN PHYSICAL PROPERTIES OF CO-DOPED La_(1/3)Sr_(2/3)Fe_(1-x)Co_xO_3

作　　者：丁晶晶[1] 王克勤[1] 朱长飞[1] 吕章明[1] 黄胜利[1] 曹烈兆[1] 阮可青[1] 

机构地区：[1]中国科技大学结构分析开放实验室,物理系,合肥230026

出　　处：《低温物理学报》2007年第2期158-162,共5页Low Temperature Physical Letters

摘　　要：本文通过对La1/3Sr2/3Fe1-xCoxO3系列样品进行X射线衍射(XRD)和变温电阻率(ρ～T)、比热(C～T)、磁化率(M～T)等测试,研究了Co掺杂对该系列样品的晶体结构和电热磁性质的影响.结果表明,随着Co掺杂量的增加,晶胞体积单调减小;电阻中电荷有序(charge ordering,CO)的特征逐渐消失.Co含量低的样品随着温度降低发生顺磁-反铁磁(PM-AFM)转变和金属-绝缘体(M-I)转变;Co含量高的样品则在磁转变温度以下表现出团簇玻璃型短程铁磁有序行为,并且在整个测量温区内具有金属导电特性.这些证明Co掺杂引起电子的局域化效应是导致体系电磁和输运行为发生变化的主要原因.In this paper, the Co-doped perovskite compoundsLa1/3Sr2/3Fe（1-x）CoxO3 （x = 0. 05,0.1,0. 65,0. 9 and 1.0 ） were synthesized and checked by X-ray diffraction （XRD）. The doping dependencies of unit cell volume, resistivity （ρ- T） , specific heat（ C - T） and magnetization （M - T） were studied. The results show that the volumes of unit cell decrease monotonously and that the charge ordering disappears gradually as the cobalt content increases. In Fe-rich samples, the electrical resistivity shows the metalsemiconductor transition, while in Co-rich samples the electrical resistivity shows metallic character. Magnetic susceptibility indicates that antiferromagnetism occurs in Fe-rich samples and ferromagnetism occurs in Co-rich samples, which is also indicated in the specific heat measurement.

关 键 词：La1/3Sr2/3Fe(1-x)CoxO3 电输运性质 磁性 比热 

分 类 号：O482[理学—固体物理]