Transitory Metastable Phases in Refractory Metals-Based Systems Solidified by Drop-Tube Processing: A First-Principles Approach

1997 ◽  
Vol 481 ◽  
Author(s):  
A. Pasturel ◽  
B. Vinet
Keyword(s):  
Phase Transformations ◽  
Rapid Solidification ◽  
Structural Stability ◽  
First Principles ◽  
Ultrahigh Vacuum ◽  
Refractory Metals ◽  
Metastable Phases ◽  
Drop Tube ◽  
First Principles Calculations ◽  
Successive Phase

ABSTRACTRefractory metals and alloys are deeply undercooled in an ultrahigh vacuum drop-tube facility. During rapid solidification, some brightness traces give evidences of two successive phase transformations. First-principles calculations of the structural stability in these systems are developed to appreciate the possibilities of obtaining metastable phases.

Transitory Metastable Phases in Refractory Metals-Based Systems Solidified by Drop-Tube Processing: A First-Principles Approach

1999 ◽  
Vol 580 ◽  
Author(s):  
C. Berne ◽  
A. Pasturel ◽  
M. Sluiter ◽  
B. Vinet
Keyword(s):  
Structural Stability ◽  
First Principles ◽  
High Vacuum ◽  
Refractory Metals ◽  
Solidification Path ◽  
Metastable Phases ◽  
Ultra High Vacuum ◽  
Drop Tube ◽  
First Principles Calculations ◽  
Σ Phase

AbstractThe solidification path of highly undercooled refractory metals and their alloys solidified in a ultra high vacuum drop-tube is shown to involve transitory metastable phases. First-principles calculations of structural stability are used to determine the possibility of obtaining metastable phases in these systems, with a view to relate this metastability with the site occupation in the σ phase in the case of the ReTa system.

scholarly journals Phase Stability and Magnetic Properties of Mn3Z (Z = Al, Ga, In, Tl, Ge, Sn, Pb) Heusler Alloys

2019 ◽  
Vol 9 (5) ◽  
pp. 964 ◽  
Author(s):  
Haopeng Zhang ◽  
Wenbin Liu ◽  
Tingting Lin ◽  
Wenhong Wang ◽  
Guodong Liu
Keyword(s):  
Magnetic Properties ◽  
Structural Stability ◽  
Phase Stability ◽  
First Principles ◽  
Magnetic Moments ◽  
Heusler Alloys ◽  
Atomic Radius ◽  
Tetragonal Distortion ◽  
Stable Phase ◽  
First Principles Calculations

The structural stability and magnetic properties of the cubic and tetragonal phases of Mn3Z (Z = Ga, In, Tl, Ge, Sn, Pb) Heusler alloys are studied by using first-principles calculations. It is found that with the increasing of the atomic radius of Z atom, the more stable phase varies from the cubic to the tetragonal structure. With increasing tetragonal distortion, the magnetic moments of Mn (A/C and B) atoms change in a regular way, which can be traced back to the change of the relative distance and the covalent hybridization between the atoms.

scholarly journals Structural Stability of Functionalized Silicene Nanoribbons with Normal, Reconstructed, and Hybrid Edges

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Sadegh Mehdi Aghaei ◽  
Ingrid Torres ◽  
Irene Calizo
Keyword(s):  
Structural Stability ◽  
First Principles ◽  
Experimental Investigations ◽  
First Principles Calculations ◽  
Zigzag Edge ◽  
Edge Structure ◽  
Practical Applications ◽  
Potential Applications ◽  
Silicene Nanoribbons ◽  
Significant Attention

Silicene, a novel graphene-like material, has attracted a significant attention because of its potential applications for nanoelectronics. In this paper, we have theoretically investigated the structural stability of edge-hydrogenated and edge-fluorinated silicene nanoribbons (SiNRs) via first-principles calculations. Various edge forms of SiNRs including armchair edge, zigzag edge, Klein edge, reconstructed Klein edge, reconstructed pentagon-heptagon edge, and hybrid edges have been considered. It has been found that fully fluorinated Klein edge SiNRs, in which each edge Si atom is terminated by three fluorine atoms, are the most stable structure. We also discovered that a hybrid edge structure of trihydrogenated Klein edge and dihydrogenated zigzag edge can increase the nanoribbon’s stability up to that of dihydrogenated armchair edge SiNR, which is known as the most stable edge-hydrogenated structure. With the attractive properties of silicene for practical applications, the obtained results will advance experimental investigations toward the development of silicene based devices.

scholarly journals Simple Model for Corrugation in Surface Alloys Based on First-Principles Calculations

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4444
Author(s):  
Monika Nur ◽  
Naoya Yamaguchi ◽  
Fumiyuki Ishii
Keyword(s):  
Simple Model ◽  
Structural Stability ◽  
First Principles ◽  
Surface Alloy ◽  
Atomic Model ◽  
First Principles Calculations ◽  
Surface Alloys ◽  
Group Iii ◽  
New Type ◽  
Atomic Radii

The structural stability of M/Ag(111)–3×3R30°  surface alloys is systematically investigated by using first-principles calculations, where M is a member of group III (B, Al, Ga, In, Tl), IV (C, Si, Ge, Sn, Pb), and V (N, P, As, Sb, Bi) elements. We focus on the corrugation parameter d which is determined by the height of the M atom from the Ag atom in the plane of the top-most atom, and the relation between atomic radii and corrugations in M/Ag(111) is obtained. The tendencies of the corrugation parameter d can be understood by using a simple hard spherical atomic model. We introduce a new type of atomic radii determined by the corrugation in surface alloys, surface alloy atomic radii, which can be useful for rapid predictions of the structures of surface alloys, not only for M/Ag (111)–3×3R30° systems but also for other surface alloys.

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