Effect of f–c hybridization on the γ → α phase transition of cerium studied by lanthanum doping

Abstract

The hybridization between the localized 4f level (f) with conduction (c) electrons in γ-Ce upon cooling has been previously revealed in single crystalline thin films experimentally and theoretically, whereas its influence on the γ→α phase transition was not explicitly verified, due to the fact that the phase transition happened in the bulk-layer, leaving the surface in the γ phase. Here in our work, we circumvent this issue by investigating the effect of alloying addition of La on Ce, by means of crystal structure, electronic transport and angle resolved photoemission spectroscopy measurements, together with a phenomenological periodic Anderson model and a modified Anderson impurity model. Our current researches indicate that the weakening of f-c hybridization is the major factor in the suppression of γ→α phase transition by La doping. The consistency of our results with the effects of other rare earth and actinide alloying additions on the γ→α phase transition of Ce is also discussed. Our work demonstrates the importance of the interaction between f and c electrons in understanding the unconventional phase transition in Ce, which is intuitive for further researches on other rare earth and actinide metals and alloys with similar phase transition behaviors.

Revisiting the effect of shear stress on the γ→α phase transition of cerium under shock loading

“…3 shows the density profile of Ce loaded with various particle velocities corresponding to recent experiments of Ce-5wt.%La alloy [47]. As argued by Wang et al [48], the La alloying should not change the electronic structure and lattice dynamics of Ce matrix significantly, due to the reasons that: 1) without f electron occupancy, La acts only as non-magnetic ion, which could tune the concentration of localized f electron of Ce; 2) La alloying could still maintain the fcc structure of Ce matrix. Considering the lack of Ce-La many-body potential, it is acceptable to model the Ce-5wt.%La alloy with the Ce EAM potential due to the very few additions of La.…”

Laser oscillation welding process control of LZ91 magnesium-lithium alloy/TC4 titanium alloys

“…In recent years, dissimilar metal welding has received widespread attention as a method to reduce weight, improve product performance, and limit costs [1] . In particular, magnesium-lithium (Mg-Li) alloy has the advantages of low density, high strength, strong rigidity, and good electromagnetic shielding, while titanium (Ti) alloy has good corrosion resistance, high heat resistance, and high strength, all are widely used in aerospace, medical, automotive and other fields [2,3] . Mg-Li alloy and Ti alloy due to the different crystal structures, there is a huge melting point difference between the two, the melting point of Ti alloy can reach 3-5 times that of Mg-Li alloy, and it is difficult for both to melt at the same time [4,5] .…”

A Theory on Increasing the Heat Transfer Performance of Building Wall

“…In China, the amount for the latter is about 15% and the ratio is increasing [1] . Meanwhile, carbon emission from buildings accounts for nearly half of that from the city [2] . Hence, it is really significant to put more emphasis on the energy-efficient building research.…”

“…That is to say, the ideal energy-saving building can properly change the thermal properties (c p (t), k(t)) of external wall with its temperature. Based on this, the objectives of the present research are: (1) to put forward an approach for determining the optimal k(t) of external wall (the c p (t) of external wall is assumed to be a constant in this study); (2) to demonstrate the application of the approach by using an illustrative example; (3) to provide guidance to researchers in building materials.…”