Al掺杂对自旋梯子化合物Sr_(14)Cu_(24)O_(41)电输运性质的影响  

The Aluminum Doping Effect on the Electronic Transport Properties of Spin Ladder Compound Sr_(14)Cu_(24)O_(41)

作　　者：陈辰[1] 邱红梅[1] 潘礼庆[2] 

机构地区：[1]北京科技大学数理学院,北京100083 [2]三峡大学新能源研究院,宜昌443002

出　　处：《材料导报》2015年第10期26-33,52,共9页Materials Reports

基　　金：国家自然科学基金(51371105)

摘　　要：利用固相反应法制备了Al掺杂的Sr14(Cu1-xAlx)24O41(x=0,0.01,0.02,0.03)系列多晶样品。X射线衍射结果表明所有样品均为单相,Al掺杂使样品晶格常数a、b发生涨落,但使晶格常数cladder逐渐减小。X射线光电子能谱结果表明Al掺杂对体系内Sr、Cu、O离子价态不存在影响,并且Al离子以+3价的形式替代了Sr14Cu24O41体系内的Cu2+,不存在其他混合价态。电阻率测量结果表明所有样品均呈半导体性,Al掺杂使体系电阻率升高。进一步分析表明所有样品存在一渡越温度Tρ,Al掺杂使Tρ发生微弱涨落。在Tρ以上,自旋梯子中单个空穴热激活对体系电导存在贡献。在Tρ以下,自旋梯子中空穴的变程跳跃电导对体系电导存在贡献。实验数据拟合结果表明Al掺杂使体系内单个空穴热激活能Δ以及局域态势垒参数T0逐渐增大。A series of Sr14 （Cu1-x Alx）24 O41（x=0,0.01,0.02,0.03） polycrystalline samples were prepared by solid-state reaction. X-ray diffraction results showed that all of the samples had a single phase. A1 doping led to the lattice parameters a and b fluctuate, but Cl,da^r decreased gradually. X-ray photoelectron spectroscopy results showed that A1 doping produced no effect on the valence of Sr, Cu and O ions. Also, A1 ions were as trivalent to substitute the Cu2＋ ions in this system respectively and they hadn＇t any other mixed valence. The results of measurement on electronic transport properties showed that all the samples were semi-conductive. A1 doping led to the increase of re- sistivity. Further analysis showed that there was a crossover temperature Te for all samples. A1 doping made Tp light- ly fluctuate. When the temperature was above Tp , the contribution to conductivity came from thermally activated sin- gle-hole. When the temperature is below Tp, the contribution to conductivity came from one-dimensional variable range hopping of holes. The fitting results showed that A1 doping made the thermally activation energy and the para- meter of potential barrier in localized state increase.

关 键 词：强关联电子系统 自旋梯子化合物 掺杂 电输运 

分 类 号：O469[理学—凝聚态物理]