CeFePO:: A heavy fermion metal with ferromagnetic correlations
CeFePO:: A heavy fermion metal with ferromagnetic correlations
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DOI：
10.1103/physrevlett.101.117206
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发表时间：
2008-09-12
影响因子：
8.6
通讯作者：
Geibel, C.
中科院分区：
文献类型：
--
作者：
Bruening, E. M.;Krellner, C.;Geibel, C.
通过测量多晶的磁化率、比热、电阻率和核磁共振谱，研究了新型高温超导体RFePnO（1-x）F（x）的同系物CeFePO的基态性质。所有的结果表明，该化合物是一种磁无序的重费米子金属，近藤温度T（K）接近10 K，索末菲系数γ = 700 mJ/mol K（2），质量增强因子为50的数量级。磁化率数据和自旋弛豫时间的分析表明，强电子相关效应源于Ce-4f电子，而不是Fe-3d电子。增强的索默-威尔逊比R = 5.5以及Korringa乘积S（0）/T（1）TK（2）接近或等于0.065，远低于1，表明存在铁磁相关。因此，CeFePO似乎是在铁磁不稳定性的一侧。
The ground state properties of CeFePO, a homologue of the new high temperature superconductors RFePnO(1-x)F(x), were studied by means of susceptibility, specific heat, resistivity, and NMR measurements on polycrystals. All the results demonstrate that this compound is a magnetically nonordered heavy fermion metal with a Kondo temperature T(K) similar to 10 K, a Sommerfeld coefficient gamma = 700 mJ/mol K(2), and a mass enhancement factor of the order of 50. Analysis of the susceptibility data and of the spin relaxation time indicates that the strong electronic correlation effects originate from the Ce-4f electrons rather than from Fe-3d electrons. An enhanced Sommerfeld-Wilson ratio R = 5.5 as well as a Korringa product S(0)/T(1)TK(2) similar or equal to 0.065 well below 1 indicate the presence of ferromagnetic correlations. Therefore, CeFePO appears to be on the nonmagnetic side of a ferromagnetic instability.