Localized to itinerant transition of f electrons in ordered Ce films on W(110)
Localized to itinerant transition of f electrons in ordered Ce films on W(110)
复制标题
局域化于 W(110) 上有序 Ce 薄膜中 f 电子的巡回跃迁
DOI：
10.1103/physrevb.97.155155
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发表时间：
2018-04-26
影响因子：
3.7
通讯作者：
Huang, L.
中科院分区：
文献类型：
--
作者：
Chen, Q. Y.;Feng, W.;Huang, L.
理解铈中同质异能γ-α跃迁的驱动力和潜在物理的一个关键问题是4f态的特征，无论它是定域的还是巡回的。利用扫描隧道显微镜、角分辨光电子能谱、密度泛函理论和单中心动力学平均场理论研究了W（110）衬底上有序Ce金属薄膜的表面形貌和电子结构。可以观察到三个几乎平坦的f带，并且在低温下直接观察到费米能级附近的弱色散准粒子带，表明低温a相中f电子和传导电子之间的杂化。随着温度的升高，杂化强度变弱，并且f电子在高温下几乎完全位于300 K。相位所观察到的f电子随温度的降低而从局域转变为巡游转变，为同构γ-α相变中4f特征的变化提供了直接的实验证据。我们的研究结果表明，f电子的特性在γ-α相变过程中起着至关重要的作用。
A key issue to understand the driving force and underlying physics in the isostructural gamma-alpha transition in Cerium is the character of the 4f states, whether it is localized or itinerant. Here the surface topography and electronic structure of the well-ordered Ce metal films on a W(110) substrate were investigated by using scanning tunneling microscopy, angle-resolved photoemission spectroscopy and density functional theory, and single-site dynamical mean-field theory calculations. Three nearly flat f bands can be observed, and a weakly dispersive quasiparticle band near the Fermi level has been directly observed at low temperature, indicating the hybridization between f electrons and conduction electrons in the low-temperature a phase. The hybridization strength becomes weaker upon increasing temperature, and the f electrons become almost fully localized at 300 K in the high-temperature. phase. The observed localized-to-itinerant transition of the f electrons with decreasing temperature gives direct experimental proof for the changes of the 4f character in the isostructural gamma-alpha phase transition. Our results suggest that the character of the f electrons plays a crucial role during the gamma-alpha phase transition.