arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1607.08680cond-mat.str-elcond-mat.supr-con
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重费米子化合物CeCo $_{1-x}$ Ni $_x$ In $_5$的超导电性和非费米液体行为

Superconductivity and non-Fermi-liquid behavior in the heavy-fermion compound CeCo$_{1-x}$Ni$_x$In$_5$

Ryo Otaka, Makoto Yokoyama, Hiroaki Mashiko, Takeshi Hasegawa, Yusei Shimizu, Yoichi Ikeda, Kenichi Tenya, Shota Nakamura, Daichi Ueta, Hideki Yoshizawa, Toshiro Sakakibara

摘要:

通过比热、磁化强度和电阻率测量研究了面外杂质对层状重费米子化合物CeCo $_{1-x}$ Ni $_x$ In $_5$超导电性和非费米液体(NFL)行为的影响.结果表明,随着x的增加,超导转变温度T $_c$从2.3 K(x=0)单调下降到0.8 K(x=0.20),当x=0.25时,超导有序消失.同时,Ni替代在x=0.25的零场下产生NFL行为,其特征在于比热除以温度C $_p$ /T和磁化率M/B的-ln T发散。磁场中x=0.25的NFL行为与纯CeCoIn $_5$中SC上临界场附近的行为非常相似,表明两种化合物都受相同的反铁磁量子临界性支配。在Ni-,Sn-和Pt-取代的CeCoIn 5之间的SC顺序的掺杂效果的相似性支持的论点,即掺杂的载流子是主要负责的SC顺序的击穿。本文的研究进一步揭示了Ce(Co,Ni)In $_5$与其它合金在超导电性抑制趋势上的定量差异,如T $_c$的降低率,dT $_c$ /dx,T $_c$的比热跃变,d($Δ$ C $_p$ /T $_c$)/dx。我们认为掺杂离子的占据位置在这些差异的起源中起着重要的作用。

英文摘要:

The effect of off-plane impurity on superconductivity and non-Fermi-liquid (NFL) behavior in the layered heavy-fermion compound CeCo$_{1-x}$Ni$_x$In$_5$ is investigated by specific heat, magnetization, and electrical resistivity measurements. These measurements reveal that the superconducting (SC) transition temperature T$_c$ monotonically decreases from 2.3 K (x=0) to 0.8 K (x=0.20) with increasing x, and then the SC order disappears above x=0.25. At the same time, the Ni substitution yields the NFL behavior at zero field for x=0.25, characterized by the -ln T divergence in specific heat divided by temperature, C$_p$/T, and magnetic susceptibility, M/B. The NFL behavior in magnetic fields for x=0.25 is quite similar to that seen at around the SC upper critical field in pure CeCoIn$_5$, suggesting that both compounds are governed by the same antiferromagnetic quantum criticality. The resemblance of the doping effect on the SC order among Ni- , Sn-, and Pt-substituted CeCoIn5 supports the argument that the doped carriers are primarily responsible for the breakdown of the SC order. The present investigation further reveals the quantitative differences in the trends of the suppression of superconductivity between Ce(Co,Ni)In$_5$ and the other alloys, such as the rates of decrease in T$_c$, dT$_c$/dx, and specific heat jump at T$_c$, d($Δ$C$_p$/T$_c$)/dx. We suggest that the occupied positions of the doped ions play an important role in the origin of these differences.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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