A Study of Epitaxial Films of Bcc Nickel on FE{001} with leed Intensity analysis and Total Energy Band Calculations

1986 ◽  
Vol 83 ◽  
Author(s):  
P. M. Marcus ◽  
V. L. Moruzzi ◽  
Z. Q. Wang ◽  
Y. S. Li ◽  
F. Jona
Keyword(s):  
Total Energy ◽  
Energy Band ◽  
Metastable Phase ◽  
Binding Energies ◽  
Gradual Change ◽  
Layer Spacing ◽  
Spin Polarized ◽  
Stable Substrate ◽  
Bulk Structure ◽  
Stable And Metastable Phases

ABSTRACTAnalysis of LEED intensities of thin films of Ni grown epitaxially on bcc Fe{001} establishes that the structure is bcc up to six layers, but with a contraction of 5% of the first layer spacing and expansion of 5% of the second layer spacing. At thicknesses above six layers there is a gradual change to a new surface and bulk structure with increasing disorder. Spin-polarized total-energy band calculations show that the bcc Ni film is stretched 1.4% from its equilibrium value and thereby changed from nonmagnetic to ferromagnetic. The calculated results on stable and metastable phases of Fe, Co, Ni and Cu show that the equilibrium lattice parameters and differences in binding energies favor mutual epitaxy for any bcc or fcc pair. There are six pairs in which a possible metastable phase is grown epitaxially on a stable substrate.

Hunting Magnetic Phases with Total-Energy Spin-Polarized Band Calculations

1985 ◽  
Vol 63 ◽  
Author(s):  
P. M. Marcus ◽  
V. L. Moruzzi ◽  
K. Schwarz
Keyword(s):  
Total Energy ◽  
Phase Diagrams ◽  
Energy Band ◽  
Spin Moment ◽  
Magnetic Phases ◽  
First Order ◽  
Spin Polarized ◽  
Volume Range

ABSTRACTComments are made on total energy band calculations as tools for exploring properties of solids; the importance of fixed spin moment calculations is noted. Use of energy - magnetisation curves to locate magnetic phases is described. Detailed results for fcc and bcc Co and Ni and phase diagrams on the magnetisation - volume plane exhibit two new phases for each metal and show that ferromagnetic fcc Co and bcc Ni break down at small volumes and make first order transitions to nonmagnetic phases in a metamagnetic volume range.

scholarly journals Metastable phases and macroheterogeneous composites

2021 ◽  
Vol 29 (1) ◽  
pp. 65-68
Author(s):  
O. V. Sukhova
Keyword(s):  
Phase Diagram ◽  
Composite Materials ◽  
Abrasive Wear ◽  
Metastable Phase ◽  
Interfacial Reactions ◽  
Metastable Phases ◽  
Metastable Phase Diagram ◽  
Rapid Dissolution ◽  
Strong Adhesion ◽  
Stable And Metastable Phases

The way to control the interfacial reactions that processes during infiltration of macroheterogeneous composite materials is suggested. The idea is to combine the stable and metastable phases in the filler’s structure which dissolves at a different rate in the molten binder. To prove this approach, the structure and gas-abrasive wear of macroheterogeneous composite materials with Cu–20Ni–20Mn binder reinforced by Fe–(9.0–10.0)B–(0.01-0.2)C filler (in wt. %) cooled at 10–20 K/s or 103–104 K/s are studied. It is shown that the wear resistance of the investigated composite materials can be enhanced by accelerating interfacial reactions between the filler and the molten binder. Therefore, the composite materials produced from a rapidly cooled Fe–B–C filler show a higher resistance to gas-abrasive wear due to formation of Fe–Fe2(B,C) metastable eutectics in its structure. This eutectics crystallizes under metastable phase diagram due to the suppression of stable Fe2(B,C) phase formation and saturation of the rest of liquid by iron in the filler cooled at 103–104 K/s. As a result of rapid dissolution of the eutectics in the molten binder during infiltration, the strong adhesion at the interfaces of the composite materials is achieved which prevents the filler from spalling out under the impacts of abrasive.

scholarly journals Oscillations of skyrmion clusters in Co/Pt multilayer nanodots

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Felipe Tejo ◽  
Felipe Velozo ◽  
Ricardo Gabriel Elías ◽  
Juan Escrig
Keyword(s):  
Total Energy ◽  
Relaxation Process ◽  
Oscillation Frequency ◽  
Equilibrium Configuration ◽  
Core Radius ◽  
Damped Oscillations ◽  
Spin Polarized

Abstract In this work we study the oscillations of the skyrmion cores in a multilayer nanodot as a function of the number of skyrmions hosted in the system. When all the skyrmions in the nanodot have the same core radius, and after applying a perpendicular spin-polarized current, a relaxation process takes place towards an equilibrium configuration that is accompanied by coherent damped oscillations of the skyrmion cores, whose frequency depends on the number of skyrmions present in the nanodot. Additionally, we found that the oscillation frequency is directly related to the total energy of the system.

scholarly journals Bonding of Gold Nanoclusters on Graphene with and without Point Defects

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2109
Author(s):  
Theodoros Pavloudis ◽  
Joseph Kioseoglou ◽  
Richard E. Palmer
Keyword(s):  
Gold Nanoclusters ◽  
Chemical Properties ◽  
Binding Energies ◽  
Hybrid Nanostructures ◽  
Au Nps ◽  
Device Stability ◽  
Spin Polarized ◽  
Technology Applications ◽  
Physical And Chemical ◽  
Electronic Chemical

Hybrid nanostructures of size-selected nanoparticles (NPs) and 2D materials exhibit striking physical and chemical properties and are attractive for many technology applications. A major issue for the performance of these applications is device stability. In this work, we investigate the bonding of cuboctahedral, decahedral and icosahedral Au NPs comprising 561 atoms on graphene sheets via 103-atom scale ab initio spin-polarized calculations. Two distinct cases we considered: (i) the Au NPs sit with their (111) facets on graphene and (ii) the NPs are oriented with a vertex on graphene. In both cases, we compare the binding energies with and without a graphene vacancy under the NP. We find that in all cases, the presence of the graphene vacancy enhances the bonding of the NPs. Significantly, in the vertex-on-graphene case, the binding energy is considerably increased by several eVs and becomes similar to the (111) facet-on-graphene case. The strain in the NPs is found to be minimal and the displacement of the carbon atoms in the immediate neighborhood of the vacancy is on the 0.1 Å scale. The work suggests the creation of stable NP-graphene systems for a variety of electronic, chemical and photonic applications.

Crystal structures, defects and transformations in the Al-(Fe,Mn)-Si alloy system

1990 ◽  
Vol 48 (4) ◽  
pp. 956-957
Author(s):  
V. Hansen ◽  
P. Skjerpe ◽  
J. Gjønnes
Keyword(s):  
Crystal Structure ◽  
Metastable Phase ◽  
Stacking Faults ◽  
Alloy System ◽  
Direct Chill ◽  
Strip Casting ◽  
Secondary Particles ◽  
Primary Particles ◽  
Stable And Metastable Phases

The alloy system Al-Fe,Mn-Si is attracting interest because of its tendency to produce quasicrystals. It is also of considerable importance in alloy technology Recent studies have in fact shown that precipitation of icosahedral particles may be the first step in the formation of secondary particles during treatment of Mn-containing alloys produced by strip-casting (Hansen, Gjønnes and Andersson 1989).Our studies of the system have been governed partly by the industrial interest They include several stable and metastable phases which appear in commercial alloys produced by direct chill- (DC-) or strip-casting. Both primary and secondary particles are studied. Especially for the metastable particles electron diffraction and microscopy is essential for determination of crystal structure as well as of defect arrangement.Previous studies included twins and stacking faults in primary particles of AL3Fe and derivation of a structure proposal for the tetragonal metastable phase AlmFe by diffraction and imaging.

Spin-polarized energy-band structure of YCo5, SmCo5, and GdCo5

1977 ◽  
Vol 16 (3) ◽  
pp. 1242-1248 ◽  
Author(s):  
S. K. Malik ◽  
F. J. Arlinghaus ◽  
W. E. Wallace
Keyword(s):  
Band Structure ◽  
Energy Band ◽  
Energy Band Structure ◽  
Spin Polarized

scholarly journals Structural, electronic and magnetic properties of the MnGa(111)-1 × 2 and 2 × 2 reconstructions: Spin polarized first principles total energy calculations

2017 ◽  
Vol 419 ◽  
pp. 286-293 ◽  
Author(s):  
Reyes Garcia-Diaz ◽  
Gregorio H. Cocoletzi ◽  
Andrada-Oana Mandru ◽  
Kangkang Wang ◽  
Arthur R. Smith ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Total Energy ◽  
First Principles ◽  
Energy Calculations ◽  
Electronic And Magnetic Properties ◽  
Spin Polarized

Electronic structure and optical properties of Ag-doped SnO2 nanoribbons

RSC Advances ◽  
2014 ◽  
Vol 4 (79) ◽  
pp. 41819-41824 ◽  
Author(s):  
Bao-Jun Huang ◽  
Feng Li ◽  
Chang-Wen Zhang ◽  
Ping Li ◽  
Pei-Ji Wang
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Total Energy ◽  
Tin Dioxide ◽  
Energy Calculation ◽  
First Principle ◽  
Electronic And Optical Properties ◽  
Total Energy Calculation ◽  
Spin Polarized

Structural, electronic and optical properties have been calculated for Tin dioxide nanoribbons (SnO2 NRs) with both zigzag and armchair shaped edges by first principle spin polarized total energy calculation.

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