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arXiv · 0811.2569

Transport properties and superconductivity in K$_{1-x}$Ln$_{x}$Fe$_2$As$_2$ (Ln=Sm, Nd and La) system

R. H. Liu·G. Wu·H. Chen·Y. L. Xie·Y. J. Yan·T. Wu·X. F. Wang·J. J. Ying·Q. J. Li·B. C. Shi·X. H. Chen
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Abstract

We prepared the samples K$_{1-x}$Ln$_{x}$Fe$_2$As$_2$ (Ln=Sm, Nd and La) with ThCr$_2$Si$_2$-type structure. These samples were characterized by X-ray diffraction, resistivity, susceptibility and thermoelectric power (TEP). Substitution of Ln (Ln=La, Nd and Sm) for K in K$_{1-x}$Ln$_{x}$Fe$_2$As$_2$ system raises the superconducting transition temperature to 34-36 K. The TEP measurements indicate that the TEP of K$_{1-x}$Ln$_{x}$Fe$_2$As$_2$ is positive, being similar to the case of the Ba$_{1-x}$K$_{x}$Fe$_2$As$_2$ system with p-type carrier. In the K$_{1-x}$Ln$_{x}$Fe$_2$As$_2$ system, the superconducting $KFe_2As_2$ with $T_c\sim 3$ K is the parent compound, and no structural and spin-density wave instabilities exist in this system.

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R. H. Liu, G. Wu, H. Chen, Y. L. Xie, Y. J. Yan, T. Wu, X. F. Wang, J. J. Ying, Q. J. Li, B. C. Shi, X. H. Chen. 2008-11-16. Transport properties and superconductivity in K$_{1-x}$Ln$_{x}$Fe$_2$As$_2$ (Ln=Sm, Nd and La) system. https://arxiv.org/abs/0811.2569

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