Chapter 9. Transition elements. Part I: Scandium, yttrium, the lanthanides, and the actinides

1978 ◽  
Vol 75 ◽  
pp. 259
Author(s):  
F. A. Hart ◽  
P. Thornton
Keyword(s):  
Transition Elements

Study of charge transfer in FeTi

1983 ◽  
Vol 41 ◽  
pp. 296-297
Author(s):  
J. Taft∅
Keyword(s):  
Charge Transfer ◽  
Charge Distribution ◽  
Electron Scattering ◽  
Periodic System ◽  
Electron Distribution ◽  
Scattering Amplitude ◽  
Transition Elements ◽  
Hartree Fock ◽  
Cscl Structure ◽  
The Right

It is well known that for reflections corresponding to large interplanar spacings (i.e., sin θ/λ small), the electron scattering amplitude, f, is sensitive to the ionicity and to the charge distribution around the atoms. We have used this in order to obtain information about the charge distribution in FeTi, which is a candidate for storage of hydrogen. Our goal is to study the changes in electron distribution in the presence of hydrogen, and also the ionicity of hydrogen in metals, but so far our study has been limited to pure FeTi. FeTi has the CsCl structure and thus Fe and Ti scatter with a phase difference of π into the 100-ref lections. Because Fe (Z = 26) is higher in the periodic system than Ti (Z = 22), an immediate “guess” would be that Fe has a larger scattering amplitude than Ti. However, relativistic Hartree-Fock calculations show that the opposite is the case for the 100-reflection. An explanation for this may be sought in the stronger localization of the d-electrons of the first row transition elements when moving to the right in the periodic table. The tabulated difference between fTi (100) and ffe (100) is small, however, and based on the values of the scattering amplitude for isolated atoms, the kinematical intensity of the 100-reflection is only 5.10-4 of the intensity of the 200-reflection.

Pt Distribution- Controlled Ni-Pt Nanocrystals via Alcohol Reduction Technique for Oxygen Reduction Reaction

2021 ◽  
Author(s):  
Kaneyuki Taniguchi ◽  
Jhon Lehman Cuya Huaman ◽  
Dausuke Iwata ◽  
Shun Yokoyama ◽  
Takatoshi Matsumoto ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Pt Nanoparticles ◽  
Cost Benefit ◽  
Reduction Reaction ◽  
Reduction Technique ◽  
Co Poisoning ◽  
Transition Elements ◽  
Poisoning Effect ◽  
Alcohol Reduction

Alloying Pt with transition elements as electrodes in fuel cells has been proposed to solve the CO poisoning effect besides cost-benefit. Consequently, the use of Ni-Pt nanoparticles (NPs) has been...

scholarly journals 3D-Based Transition hpq/hp-Adaptive Finite Elements for Analysis of Piezoelectrics

2021 ◽  
Vol 11 (9) ◽  
pp. 4062
Author(s):  
Grzegorz Zboiński ◽  
Magdalena Zielińska
Keyword(s):  
Finite Elements ◽  
Numerical Solutions ◽  
High Stress ◽  
Continuous Change ◽  
Transition Elements ◽  
Finite Element Approximations ◽  
Element Size ◽  
Piezoelectric Elements ◽  
Mechanical Models ◽  
Transition Models

This paper concerns the algorithm of transition piezoelectric elements for adaptive analysis of electro-mechanical systems. In addition, effectivity of the proposed elements in such an analysis is presented. The elements under consideration are assigned for joining basic elements which correspond to the mechanical models of either the first or higher order, while the electric model is of arbitrary order. In this work, three variants of the transition models are applied. The first one assures continuity of displacements between the basic models and continuity of electric potential between these models, as well. The second transition piezoelectric model guarantees additional continuity of the stress field between the basic models. The third transition model additionally enables continuous change of the strain state between the basic models. Based on the mentioned models, three types of the corresponding transition finite elements are introduced. The applied finite element approximations are hpq/hp-adaptive ones, which allows element-wise changes of the element size parameter h, and the element longitudinal and transverse orders of approximation, respectively, p and q, depending on the error level. Numerical effectiveness of the models and their approximations is investigated in the contexts of: ability to remove high stress gradients between the basic and transition models, and convergence of the numerical solutions for the model problems of piezoelectrics with and without the proposed transition elements.

Disorder effect of 3d transition elements in DO3 Heusler alloy Mn2FeAl

2021 ◽  
Vol 118 (13) ◽  
pp. 132408
Author(s):  
Bing Lv ◽  
Pei Liu ◽  
Yu Miao ◽  
Zhongyuan Lian ◽  
Mingsu Si ◽  
...  
Keyword(s):  
Heusler Alloy ◽  
Transition Elements ◽  
Disorder Effect
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