Irrotational core in deformed nuclei

1982 ◽  
Vol 60 (3) ◽  
pp. 337-339
Author(s):  
B. A. Bishara
Keyword(s):  
Rare Earth ◽  
Shell Model ◽  
Rare Earths ◽  
Axially Symmetric ◽  
Deformed Nuclei ◽  
The Core ◽  
Rotator Model ◽  
Rare Earth Nuclei ◽  
Rotationally Invariant

The construction of the "rotationally invariant core" (RIC) of the governor model for the deformed even–even nuclei has been studied for the rare earths. The comparison of the RIC nucleons with the shell model configurations shows that the model's assumption of "spherical" RIC is almost true only for the axially symmetric deformed nuclei. For asymmetric triaxial deformed nuclei, the study supports the assumption of the governor asymmetric rotator model, namely that the RIC is an axially symmetric prolate. The core shrinkage at higher rotational energies has been also calculated for several rare-earth nuclei.

Quasiparticle levels in rotating rare earth nuclei: A cranked shell-model dictionary

1986 ◽  
Vol 35 (1) ◽  
pp. 15-122 ◽  
Author(s):  
R. Bengtsson ◽  
S. Frauendorf ◽  
F.-R. May
Keyword(s):  
Rare Earth ◽  
Shell Model ◽  
Rare Earth Nuclei

A Rigorous Application of the Collective Model to Some Rare Earth Nuclei

1975 ◽  
Vol 53 (6) ◽  
pp. 559-573 ◽  
Author(s):  
B. Hird ◽  
K. H. Huang
Keyword(s):  
Collective Model ◽  
Band Spectrum ◽  
Shape Parameters ◽  
Axially Symmetric ◽  
Complete Spectrum ◽  
The Core ◽  
Level Sequence ◽  
Rare Earth Nuclei ◽  
Correct Level ◽  
Good Agreement

The collective model of an odd neutron in an axially symmetric deformed Woods–Saxon potential, coupled to a rotating core, and containing the full RPC and pairing corrections has been used to predict the full low lying rotational band spectrum of the nuclei with N = 91 to 97. Only three adjustable parameters were used in each nucleus to fit the complete spectrum. It was possible in several nuclei to obtain the correct level sequence and in most to confirm level assignments, and the adjusted parameters were in good agreement with accepted values. However, the accuracy of this method is insufficient, in most nuclei, to provide reliable predictions for as yet unidentified bands. The lack of good overall agreements in the low lying spectra of these nuclei confirms that the core shape parameters do change from one band to another.

Phenomenological Description of High Spin States in Doubly Even Rare Earths

1975 ◽  
Vol 53 (17) ◽  
pp. 1651-1658 ◽  
Author(s):  
C. A. Heras ◽  
S. M. Abecasis
Keyword(s):  
Rare Earth ◽  
High Spin ◽  
Rare Earths ◽  
Energy Levels ◽  
Specific Model ◽  
Global Structure ◽  
Phenomenological Description ◽  
Spin States ◽  
High Spin States ◽  
Rare Earth Nuclei

Without recourse to a specific model, assuming only that the global structure of spectra is rotational, a good fit of energy levels in doubly even rare earth nuclei is achieved, including the so-called backbending at high spins.

Representations of sl(3, IR) with half-integral spin bands

1976 ◽  
Vol 54 (11) ◽  
pp. 1114-1123 ◽  
Author(s):  
G. Rosensteel ◽  
D. J. Rowe
Keyword(s):  
Rare Earth ◽  
Harmonic Analysis ◽  
Principal Series ◽  
Algebraic Model ◽  
Wave Functions ◽  
Irreducible Representations ◽  
Deformed Nuclei ◽  
Rare Earth Nuclei ◽  
Integral Spin ◽  
Collective States

A series of irreducible representations of sl(3,IR) is constructed with half-integral spin bands which parallels the principal series of SL(3,IR). While the principal series for SL(3,IR) was shown by Weaver and Biedenharn to be applicable to even–even deformed nuclei, the series constructed here applies to odd mass nuclei. It is shown how parity is included in an SL(3,IR) algebraic model. A second (cuspidal parabolic) series of representations of SL(3,IR) is constructed, which is required for the harmonic analysis of wave functions on SL(3,IR), a necessary preliminary to the application of the results of the SL(3,IR) model in a full microscopic treatment of deformed nuclei. It is shown that the cuspidal parabolic series has undesirable properties for the description of collective states in rare-earth nuclei.

Determination through symmetry arguments of the various contributions to the self polarisation field at rare earth nuclei in cubic compounds

1979 ◽  
Vol 40 (C5) ◽  
pp. C5-56-C5-57 ◽  
Author(s):  
E. Belorizky ◽  
Y. Berthier ◽  
R. A.B. Devine ◽  
P. M. Levy ◽  
J. J. Niez
Keyword(s):  
Rare Earth ◽  
The Self ◽  
Polarisation Field ◽  
Rare Earth Nuclei

A glance on rare earth oxides: importance, reserves, demand, applications, critical uncertainties, global economy, and zeta potential characterization

2020 ◽  
Vol 05 ◽  
Author(s):  
Silas Santos ◽  
Orlando Rodrigues ◽  
Letícia Campos
Keyword(s):  
Rare Earth ◽  
Zeta Potential ◽  
Sample Preparation ◽  
Rare Earths ◽  
Smart Materials ◽  
Global Economy ◽  
Materials Science ◽  
Functional Materials ◽  
Rare Earth Oxides ◽  
Interparticle Forces

Background: Innovation mission in materials science requires new approaches to form functional materials, wherein the concept of its formation begins in nano/micro scale. Rare earth oxides with general form (RE2O3; RE from La to Lu, including Sc and Y) exhibit particular proprieties, being used in a vast field of applications with high technological content since agriculture to astronomy. Despite of their applicability, there is a lack of studies on surface chemistry of rare earth oxides. Zeta potential determination provides key parameters to form smart materials by controlling interparticle forces, as well as their evolution during processing. This paper reports a study on zeta potential with emphasis for rare earth oxide nanoparticles. A brief overview on rare earths, as well as zeta potential, including sample preparation, measurement parameters, and the most common mistakes during this evaluation are reported. Methods: A brief overview on rare earths, including zeta potential, and interparticle forces are presented. A practical study on zeta potential of rare earth oxides - RE2O3 (RE as Y, Dy, Tm, Eu, and Ce) in aqueous media is reported. Moreover, sample preparation, measurement parameters, and common mistakes during this evaluation are discussed. Results: Potential zeta values depend on particle characteristics such as size, shape, density, and surface area. Besides, preparation of samples which involves electrolyte concentration and time for homogenization of suspensions are extremely valuable to get suitable results. Conclusion: Zeta potential evaluation provides key parameters to produce smart materials seeing that interparticle forces can be controlled. Even though zeta potential characterization is mature, investigations on rare earth oxides are very scarce. Therefore, this innovative paper is a valuable contribution on this field.

China and the Geopolitics of Rare Earths

2017 ◽  
Author(s):  
Sophia Kalantzakos
Keyword(s):  
Rare Earth ◽  
Rare Earths ◽  
Resource Competition ◽  
Renewable Energy Sources ◽  
High Tech ◽  
Trade Dispute ◽  
Policy Responses ◽  
Economic Statecraft ◽  
The Rare Earth

In 2010, because of a geopolitical incident between China and Japan, seventeen elements of the periodic table known as rare earths became notorious overnight. An “unofficial” and temporary embargo of rare-earth shipments to Japan alerted the world to China’s near monopoly position on the production and export of these indispensable elements for high-tech, defense, and renewable energy sources. A few months before the geopolitical confrontation, China had chosen to substantially cut export quotas of rare earths. Both events sent shockwaves across the markets, and rare-earth prices skyrocketed, prompting reactions from industrial nations and industry itself. The rare-earth crisis is not a simple trade dispute, however. It also raises questions about China’s use of economic statecraft and the impacts of growing resource competition. A detailed and nuanced examination of the rare-earth crisis provides a significant and distinctive case study of resource competition and its spill-over geopolitical effects. It sheds light on the formulation, deployment, longevity, effectiveness, and, perhaps, shortsightedness of policy responses by other industrial nations, while also providing an example of how China might choose to employ instruments of economic statecraft in its rise to superpower status.

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