Competition between Kondo and RKKY exchange couplings in Pu 1-x Am x alloys: Density functional theory with static Hartree-Fock and dynamic Hubbard-I approximations
Competition between Kondo and RKKY exchange couplings in Pu 1-x Am x alloys: Density functional theory with static Hartree-Fock and dynamic Hubbard-I approximations
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DOI：
10.1103/physrevb.78.060401
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发表时间：
2008-06
影响因子：
3.7
通讯作者：
M. J. Han;X. Wan;S. Savrasov
中科院分区：
文献类型：
--
作者：
M. J. Han;X. Wan;S. Savrasov
为了阐明近藤效应在屏蔽钚5 f-电子局域磁矩中的作用以及它对RKKY相互作用的竞争，我们用密度泛函理论结合静态Hartree Fock和动态Hubbard 1近似计算了Pu{1-x}Am{x}系统的近藤交换J_K和RKKY交换J_RKKY耦合强度随x的变化.我们发现，尽管随着Am的掺杂，原子体积变大，但J_K增加，这是由于在费米能级附近f和传导电子之间的杂化意外增强。同时，RKKY交换被示出为随着x的增加而平滑地减小。我们的研究结果表明，近藤效应应该是强大的对这种合金的原子间距的增加。
To clarify the role of the Kondo effect in screening local magnetic moments of Plutonium 5f--electrons as well as its competition to the RKKY interactions we use a combination of density functional theory with static Hartree Fock and dynamic Hubbard 1 approximations to calculate the strength of both the Kondo exchange, J_K, and of the RKKY exchange, J_RKKY, couplings for Pu{1-x}Am{x} system as a function of x. We find that J_K increases despite the atomic volume gets larger with the Am doping due to unexpected enhancement of hybridization between f and conduction electrons in the vicinity of the Fermi level. At the same time, the RKKY exchange is shown to reduce smoothly with increasing x. Our results imply that the Kondo effect should be robust against the increase in interatomic spacing of this alloy.