paper

Transport properties and superconductivity in K $_{1 - x}$ Ln $_{x}$ Fe $_{2}$ As $_{2}$ (Ln=Sm, Nd and La) system

arXiv:0811.2569

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 $K F e_{2} A s_{2}$ with $T_{c} \sim 3$ K is the parent compound, and no structural and spin-density wave instabilities exist in this system.

4 pages, 4 figures

Transport properties and superconductivity in K1−x​Lnx​Fe2​As2​ (Ln=Sm, Nd and La) system

Abstract

Transport properties and superconductivity in K $_{1 - x}$ Ln $_{x}$ Fe $_{2}$ As $_{2}$ (Ln=Sm, Nd and La) system