Emergence of reentrant metal-nonmetal transition in Pr0.85Ce0.15Ru4P12 and Pr(Ru0.95Rh0.05)4P12
Emergence of reentrant metal-nonmetal transition in Pr0.85Ce0.15Ru4P12 and Pr(Ru0.95Rh0.05)4P12
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Pr0.85Ce0.15Ru4P12 和 Pr(Ru0.95Rh0.05)4P12 中出现重入金属-非金属转变
DOI：
10.1103/physrevb.89.075131
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
and Kazuaki Iwasa
中科院分区：
文献类型：
--
作者：
Kotaro Saito;Claire Laulhe;Takahiro Sato;Lijie Hao;Jean-Michel Mignot;and Kazuaki Iwasa
通过磁化率、x射线超晶格反射和非弹性中子散射（INS）测量研究了铈和铑取代材料中的金属-非金属转变。在低温下磁化率的饱和表明这两种化合物的Pr位为单线态基态。这一发现与在有序相中发现的单重态和三重态基态的交错顺序相反，这导致了磁化率的发散。两种化合物的x射线超晶格反射强度在45 K以下发展，在10 K以下迅速下降，同时电阻率降低。INS实验表明，这两种化合物的4个电子态从多极有序相（10K）的有序参数对应的两种不同的晶体场（CF）能级模式急剧变化到10K以下的几乎均匀的CF能级模式。在Pr位点的均匀CF基态没有与交错排序模式和电子间隙形成相关的自由度。因此，所取代的体系在最低温度下表现为可重入金属态。这些现象可能源于原子取代引起的有效电子掺杂。
The metal-nonmetal transition in Ce- and Rh-substitutedwas investigated through magnetic susceptibility, x-ray superlattice reflection, and inelastic neutron scattering (INS) measurements. The saturation in the magnetic susceptibility at low temperatures suggests a singlet ground state for Pr sites in both compounds. This finding is in contrast to the staggered order of singlet and triplet ground states found in the ordered phase of, which leads to a diverging susceptibility. The intensities of x-ray superlattice reflections of both compounds develop below 45 K and decrease rapidly below 10 K with a simultaneous decrease in electrical resistivity. INS experiments reveal that 4electron states in both compounds change drastically from two distinct crystal field (CF) level schemes corresponding to an order parameter in the multipole ordered phase (10K) to a nearly uniform CF level scheme below 10 K. The uniform CF ground state at the Pr sites carries no degree of freedom relevant to the staggered ordering pattern and electronic gap formation. Therefore, the substituted systems exhibit a reentrant metallic state at the lowest temperature. These phenomena may originate from effective electron doping due to atomic substitution.