On sodium clusters in C60 fullerides

1997 ◽  
Vol 75 (1) ◽  
pp. 77-82 ◽  
Author(s):  
M. Apostol ◽  
F. Rachdi ◽  
C. Goze ◽  
L. Hajji
Keyword(s):  
Electric Charge ◽  
The Body ◽  
Electron Charge ◽  
Body Centered Cubic ◽  
Fermi Theory ◽  
Fermi Model ◽  
Thomas Fermi ◽  
Sodium Clusters ◽  
Alkali Fullerides

Sodium (Na) clusters in octahedral cages of Na-intercalated fullerides Na6C60 and Na11C60 are studied within a Thomas–Fermi model. It is shown that the tetrahedral Na4 cluster in Na6C60 has an electric charge ~ +2.7 (in electron charge units), while the body-centered cubic Na9 cluster in Na11C60 is almost electrically neutral. Keywords: sodium clusters, alkali fullerides, Thomas–Fermi theory, ionization charge.

Voids in Irradiated Tungsten and Molybdenum

1969 ◽  
Vol 27 ◽  
pp. 190-191
Author(s):  
Robert C. Rau ◽  
Robert L. Ladd
Keyword(s):  
Melting Point ◽  
Fast Neutron ◽  
Neutron Irradiation ◽  
Elevated Temperatures ◽  
Irradiation Temperature ◽  
The Body ◽  
Face Centered Cubic ◽  
Body Centered Cubic ◽  
Cubic Metals ◽  
Face Centered

Recent studies have shown the presence of voids in several face-centered cubic metals after neutron irradiation at elevated temperatures. These voids were found when the irradiation temperature was above 0.3 Tm where Tm is the absolute melting point, and were ascribed to the agglomeration of lattice vacancies resulting from fast neutron generated displacement cascades. The present paper reports the existence of similar voids in the body-centered cubic metals tungsten and molybdenum.

Thomas-Fermi Theory of an Inhomogeneous Electron Liquid Generalized to Incorporate Density Gradients

1998 ◽  
Vol 36 (2) ◽  
pp. 91-103 ◽  
Author(s):  
C. Amovilli ◽  
N. H. March ◽  
T. G. Schmalz ◽  
D. J. Klein
Keyword(s):  
Density Gradients ◽  
Fermi Theory ◽  
Thomas Fermi

Comparison of Variational Solutions of the Thomas-Fermi Model in Terms of the Corrected Ionization Energy

1987 ◽  
Vol 42 (9) ◽  
pp. 943-947
Author(s):  
I. Agil ◽  
A. Alharkan ◽  
H . Alhendi ◽  
A. Alnaghmoosh
Keyword(s):  
Ionization Energy ◽  
Trial Function ◽  
Binding Energies ◽  
Initial Slope ◽  
Fermi Model ◽  
Thomas Fermi ◽  
Variational Solutions ◽  
Comparison Of The Results

It is shown that leading corrections, to the ionization energy, of many-electrons atom, can be expressed as leading corrections of initial slope of trial variational solutions of the Thomas-Fermi equation. Some variational solutions with different initial slopes are compared. A comparison of the results shows, that as far as the binding energies are concerned a trial function with its slope not close to the (negative) Baker’s constant may not be suited.

New Thomas-Fermi theory: A test

1982 ◽  
Vol 25 (4) ◽  
pp. 2399-2401 ◽  
Author(s):  
Lester L. DeRaad ◽  
Julian Schwinger
Keyword(s):  
Fermi Theory ◽  
Thomas Fermi

MINIMAL KNOTTING NUMBERS

2009 ◽  
Vol 18 (08) ◽  
pp. 1159-1173 ◽  
Author(s):  
CASEY MANN ◽  
JENNIFER MCLOUD-MANN ◽  
RAMONA RANALLI ◽  
NATHAN SMITH ◽  
BENJAMIN MCCARTY
Keyword(s):  
The Body ◽  
Computer Algorithm ◽  
Face Centered Cubic ◽  
Body Centered Cubic ◽  
Cubic Lattice ◽  
The Face ◽  
Face Centered ◽  
Body Centered Cubic Lattice

This article concerns the minimal knotting number for several types of lattices, including the face-centered cubic lattice (fcc), two variations of the body-centered cubic lattice (bcc-14 and bcc-8), and simple-hexagonal lattices (sh). We find, through the use of a computer algorithm, that the minimal knotting number in sh is 20, in fcc is 15, in bcc-14 is 13, and bcc-8 is 18.

Poisson's Ratio for Central-Force Polycrystals

1976 ◽  
Vol 31 (12) ◽  
pp. 1539-1542 ◽  
Author(s):  
H. M. Ledbetter
Keyword(s):  
Electron Energy ◽  
Poisson Ratio ◽  
The Body ◽  
Central Force ◽  
Face Centered Cubic ◽  
Polycrystalline Aggregate ◽  
Body Centered Cubic ◽  
The Face ◽  
Predicted Values ◽  
Face Centered

Abstract The Poisson ratio υ of a polycrystalline aggregate was calculated for both the face-centered cubic and the body-centered cubic cases. A general two-body central-force interatomatic potential was used. Deviations of υ from 0.25 were verified. A lower value of υ is predicted for the f.c.c. case than for the b.c.c. case. Observed values of υ for twenty-three cubic elements are discussed in terms of the predicted values. Effects of including volume-dependent electron-energy terms in the inter-atomic potential are discussed.

Rapid Thermal Transformation of A-15 Crystal Structure Metallic Thin Films

1995 ◽  
Vol 387 ◽  
Author(s):  
M. J. O'Keefe ◽  
C. L. Cerny
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Physical Vapor Deposition ◽  
Thermal Transformation ◽  
The Body ◽  
Cubic Phase ◽  
Body Centered Cubic ◽  
Body Center Cubic

AbstractPhysical vapor deposition of Group VI elements (Cr, Mo, W) can lead to the formation of a metastable A-15 crystal structure under certain processing conditions. Typically, a thermally induced transformation of the metastable A-15 structure into the equilibrium body centered cubic structure has been accomplished by conventional furnace annealing at T/Tm ≈ 0.3 from tens of minutes to several hours. In this study we report on the use of rapid thermal annealing to transform sputter deposited A- 15 crystal structure tungsten and chromium thin films into body centered cubic films within the same temperature range but at times on the order of one minute. The minimum annealing times and temperatures required for complete transformation of the A-15 phase into the BCC phase varied from sample to sample, indicating that the transformation was dependent on the film characteristics. The electrical resistivity of A-15 Cr and W films was measured before and after rapid thermal annealing and was found to significantly decrease after transformation into the body center cubic phase.

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