Hole Concentration Compensation Effect and Superconducting Properties of Nd1+xBa2-xCu3O7-δ
Hole Concentration Compensation Effect and Superconducting Properties of Nd1+xBa2-xCu3O7-δ
复制标题
Nd1+xBa2-xCu3O7-δ的空穴浓度补偿效应与超导性能
DOI：
10.1143/jjap.27.l67
复制
发表时间：
1988
影响因子：
1.5
通讯作者：
K. Masuda
中科院分区：
文献类型：
--
作者：
K. Takita;H. Akinaga;H. Katoh;H. Asano;K. Masuda
本文研究了Nd1+xBa2-xCu3O7-δ体系的超导转变温度Tc和常态电阻率随x的变化规律，并用x射线粉末衍射结合Rietveld法在室温下测定了Nd1+xBa2-xCu3O7-δ体系的晶体结构。当x=0和0.05时，样品的Tc均在90 K以上，除了在x=0.25 ~ 0.30附近（Tc≤35 K）处，Tc随x单调下降，在x=0.40处变为半导体。化合物的正交畸变随x的增加而减小，当x=0.20时，化合物变为四边形。Tc随x的变化对正交-四方相变不敏感。基于过量Nd可能的空穴浓度补偿效应，讨论了铜氧化物型超导体中Tc与空穴浓度的关系。
The superconducting transition temperature Tc and normal-state resistivity have been investigated as a function of x for the Nd1+xBa2-xCu3O7-δ system, whose crystal structures have been determined at room temperature by X-ray powder diffraction combined with the Rietveld method. Tc of the samples with x=0 and 0.05 is above 90 K, which decreases monotonically with x except for around x=0.25∼0.30 (Tc≃35 K) and the sample becomes semiconducting at x=0.40. The orthorhombic distortion of the compounds decreases with x and the compound becomes tetragonal at x=0.20. The variation of Tc with x is insensitive to the orthorhombic-tetragonal phase transition. A correlation of Tc with hole concentration in copper-oxide-type superconductors is discussed based on a possible hole concentration compensation effect of excess Nd.