Nd_(2-x)Ce_xCuO_(4-δ)晶体的生长及性质  

Growth and transport properties of Nd_(2-x)Ce_xCuO_(4-δ) single crystals

作　　者：李配军[1] 吴王杰[1] 韩仙华[1] 白忠[1] 蒋敏[1] 傅强[1] 王智河[2] 陈法佐[1] 

机构地区：[1]解放军理工大学理学院,江苏南京211101 [2]南京大学固体微结构国家重点实验室,江苏南京210093

出　　处：《解放军理工大学学报（自然科学版）》2008年第3期255-258,共4页Journal of PLA University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(10174033)

摘　　要：为了从电子型超导体的角度探求高温超导体的机理，采用自助熔剂缓冷法成功地生长出了高质量的Nd2-xCexCuO4-δ单晶，并由X射线衍射和扫描电镜证明了晶体是高质量的单晶。用物性测量仪在0～9T范围内分别测量了磁场平行和垂直样品表面的电阻转变曲线。结果显示，样品零场下零电阻转变温度约为21K，在80～150K范围，电阻随温度的变化关系可以用幂指数关系R（T）-T^2。来描述，但是在低温区表现出N型反常行为。在起始转变温度以下有一个很大的电阻突起峰，且受到磁场的抑制。晶体表现为类重费米子系统性质。样品特征温度为23．1K。In order to understand the mechanism of high-To superconductivity from the electron-doped superconductor, Nd2-xCexCuO4-δ single crystals were successfully grown by self-flux slow cooling method. Good quality crystals can be verified by X-ray diffraction pattern and scanning electron microscopy observation. The resistive transition curves along the c-axis in different magnetic field for H//ab-plane and H// c-axis were measured, respectively. The zero-resistance temperature is Tc0≈21 K. The temperature dependence of the resistance can be described with power R（T）-T^2 between 80 to 150 K, There displays N-type normal behavior in the low temperature region. There is a resistance peak under the transition temperature and the peak is restrained by the magnetic field. The result shows that the crystals have similar properties with the classical heavy-fermion systems. The character temperature is 23.1 K.

关 键 词：Nd2-xCexCuO4-δ 单晶 缓冷法 输运性质 

分 类 号：O511.4[理学—低温物理]