THE PHASE DIAGRAM OF THE KONDO LATTICE
THE PHASE DIAGRAM OF THE KONDO LATTICE
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DOI：
10.1007/978-94-011-5080-4_17
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发表时间：
1979-09
期刊：
影响因子：
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通讯作者：
C. Lacroix
中科院分区：
文献类型：
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作者：
C. Lacroix
由于长程RKKY相互作用I（Ri-Rj）和局域负s-f交换J（近藤效应）之间的竞争，重费米子系统表现出许多不寻常的现象，因此从实验和理论的角度都受到了广泛的关注：基态可以是磁性的或磁性的取决于这些相互作用的相对强度，λ =TK/I（TK = 1/pexp（1/pJ）是特征近藤能量）[1]，可以通过施加压力或合金化来改变。在T=0° K时，λ的临界值λc将两相分开，并且在许多情况下在λ附近观察到非费米液体行为[2]。在一些重费米子化合物中，超导性也可以稳定在这个临界点附近[3]。自从Doniach [1]的第一篇论文以来，已经有大量的文章致力于这个问题。本文的目的不是对这个问题进行综述，而是强调几点，如能带填充的重要性，位间交换相互作用的作用和铁磁和反铁磁位间交换的本质区别。
Heavy Fermions systems have received much attention from both experimental and theoretical points of view because they exhibit many unusual phenomena due to the competition between the long range RKKY interactions, I(Ri-Rj), and the local negative s-f exchange, J, responsible for the Kondo effect: the ground state can be either magnetic or nonmagnetic depending on the relative strength of these interactions, λ =TK/I (TK≈1/pexp(1/pJ) is the characteristic Kondo energy) [1], which can be varied by applying pressure or alloying. At T=0° K a critical value of λ, λc, separates the two phases and non-Fermi liquid behavior has been observed around λcin many cases [2]. Also in several heavy fermions compounds superconductivity can be stabilized close to this critical point [3]. Since the first paper of Doniach [1] there have been a large number of articles devoted to this problem. The purpose of the present paper is not to give a review on this problem but rather to stress a few points such as the importance of the band filling, the role of intersite exchange interactions and the essential difference between ferro-and antiferromagnetic intersite exchange.