Impurity and doping effects on the pseudoenergy gap in CeNiSn: A Sn NMR study.
Impurity and doping effects on the pseudoenergy gap in CeNiSn: A Sn NMR study.
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杂质和掺杂对 CeNiSn 中赝能隙的影响：Sn NMR 研究。
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
Fujii
中科院分区：
文献类型：
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作者：
Nakamura;Kitaoka;Asayama;Takabatake;Nakamoto;Tanaka;Fujii
在非化学计量化合物 CeNi1.01Sn 和取代化合物 CeNi12xMxSn ~M5Cu,Co 中测量 Sn 核自旋晶格弛豫率 1/T1 和奈特位移 K！为了揭示杂质和/或载流子掺杂对 CeNiSn 中 V 形带隙态的影响，制备了 Ce12xLaxNiSn 和 Ce12xLaxNiSn。从 1/T1 的 T 依赖性的详细分析可以看出，态密度 ~DOS!对于 CeNi1.01Sn，仅在费米能级处诱导，而对于取代的化合物，在费米能级附近的有限能量范围内，DOS 随着掺杂剂的增加而逐渐增加。 Co和La分别取代Ni和Ce位点将带隙态改变为非磁性费米液体态，而用x取代Cu则将带隙态转变为非磁性费米液体态。 0.06 产生反铁磁~AF！基态。认为AF级是通过V型能隙的快速塌缩和费米能级DOS的增加的共同作用来实现的。已发现它会导致磁性基态和非磁性费米液体态，从而分别将电子和空穴掺杂到重整化导带中。
Measurements of Sn nuclear spin-lattice relaxation rate, 1/T1 , and Knight shift, K, in the offstoichiometric compound CeNi1.01Sn and the substituted compounds CeNi12xMxSn ~M5Cu,Co! and Ce12xLaxNiSn have been made in order to unravel the impurity and/or carrier doping effects on the V-shaped gapped state in CeNiSn. From the detailed analysis of the T dependence of 1/T1 , it is shown that the density of states ~DOS! is induced just at the Fermi level for CeNi1.01Sn, whereas the DOS increases progressively with the dopant in a finite-energy range near the Fermi level for the substituted compounds. The respective substitution of Co and La into Ni and Ce sites changes the gapped state into the nonmagnetic Fermi-liquid state, whereas the replacement of Ni by Cu with x. 0.06 gives rise to the antiferromagnetic ~AF! ground state. It is suggested that the AF order is realized by the combined effect of the rapid collapse of the V-shaped gap and the increase of the DOS at the Fermi level. It has been found to lead to the magnetic ground state and the nonmagnetic Fermi-liquid state to dope electrons and holes into the renormalized conduction bands, respectively.