An electronic structure perspective on glass-forming ability in metallic glasses
An electronic structure perspective on glass-forming ability in metallic glasses
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DOI：
10.1063/1.3327337
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发表时间：
2010-02
影响因子：
4
通讯作者：
H. Yu;W. Wang;H. Bai
中科院分区：
文献类型：
--
作者：
H. Yu;W. Wang;H. Bai
研究了未掺杂母体化合物LaFeAsO和LaNiAsO的热电势和能斯特效应。铁基LaFeAsO的热电势和能斯特信号均明显大于镍基LaNiAsO。此外，在结构相变温度和自旋密度波(SDW)型反铁磁(AFM)有序温度以下，观察到铁基LaFeAsO的热电势和能斯特效应都发生了突变。另一方面，在镍基LaNiAsO中能斯特效应很小，而且它与温度的关系很弱，这让人想起正常金属的情况。我们认为，在LaFeAsO的霍尔效应和能斯特效应的反常温度关系中，自旋散射率的自旋散射率受SDW级数的影响起着重要的作用。LaFeAsO和LaNiAsO系统的行为对比表明，LaFeAsO系统与LaNiAsO系统有根本的不同，这可能为揭示铁基系统高T(C)超导电性的机制提供线索。
The thermopower and Nernst effect were investigated for undoped parent compounds LaFeAsO and LaNiAsO. Both the thermopower and Nernst signal in iron-based LaFeAsO are significantly larger than those in nickel-based LaNiAsO. Furthermore, abrupt changes in both the thermopower and Nernst effect are observed below the structural phase transition temperature and spin-density wave (SDW) type antiferromagnetic (AFM) order temperature in Fe-based LaFeAsO. On the other hand, the Nernst effect is very small in the Ni-based LaNiAsO and it is weakly temperature-dependent, reminiscent of the case in normal metals. We suggest that the effect of SDW order on the spin scattering rate should play an important role in the anomalous temperature dependence of the Hall effect and Nernst effect in LaFeAsO. The contrasting behaviour between the LaFeAsO and LaNiAsO systems implies that the LaFeAsO system is fundamentally different from the LaNiAsO system and this may provide clues to the mechanism of high T(c) superconductivity in Fe-based systems.