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arXiv · 0807.4328

Narrow superconducting window in Ni-doped LaFeAsO

Guanghan Cao·Shuai Jiang·Xiao Lin·Cao Wang·Yuke Li·Zhi Ren·Qian Tao·Jianhui Dai·Zhu'an Xu·Fu-Chun Zhang
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Abstract

We have studied Ni-substitution effect in LaFe$_{1-x}$Ni$_{x}$AsO ($0\leq x \leq0.1$) by the measurements of x-ray diffraction, electrical resistivity, magnetic susceptibility, and heat capacity. The nickel doping drastically suppresses the resistivity anomaly associated with spin-density-wave ordering in the parent compound. Superconductivity emerges in a narrow region of $0.03\leq x \leq0.06$ with the maximum $T_c$ of 6.5 K at $x$=0.04, where enhanced magnetic susceptibility shows up. The upper critical field at zero temperature is estimated to exceed the Pauli paramagnetic limit. The much lowered $T_c$ in comparison with LaFeAsO$_{1-x}$F$_{x}$ system is discussed.

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Guanghan Cao, Shuai Jiang, Xiao Lin, Cao Wang, Yuke Li, Zhi Ren, Qian Tao, Jianhui Dai, Zhu'an Xu, Fu-Chun Zhang. 2009-04-16. Narrow superconducting window in Ni-doped LaFeAsO. https://doi.org/10.1103/physrevb.79.174505

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