Crystal equilibrium and lattice dynamics of face-centered cubic metals

1978 ◽  
Vol 56 (4) ◽  
pp. 447-452 ◽  
Author(s):  
O. P. Gupta ◽  
H. L. Kharoo ◽  
M. P. Hemkar
Keyword(s):  
Lattice Dynamics ◽  
Present Theory ◽  
Face Centered Cubic ◽  
Fcc Metals ◽  
Cubic Metals ◽  
Nearest Neighbours ◽  
Screening Parameter ◽  
Crystal Dynamics ◽  
Face Centered ◽  
Ionic Lattice

A lattice dynamical model that assumes short range pairwise forces effective up to second nearest neighbours and electron–ion interaction on the lines of Bhatia is considered to study the crystal dynamics of fcc metals. The authors consider an appropriate value of the screening parameter and the band structure effects have been introduced in a satisfactory manner in the present calculations. The volume force is averaged over the whole Wigner–Seitz sphere. The ionic lattice is in equilibrium in a medium of electrons. The present theory has been satisfactorily applied to compute dispersion curves, Debye characteristic temperatures, and temperature dependence on the Debye–Waller factors of thorium.

Angular Forces in the Lattice Dynamics of Face-Centered Cubic Metals

1967 ◽  
Vol 164 (3) ◽  
pp. 895-899 ◽  
Author(s):  
P. S. Yuen ◽  
Y. P. Varshni
Keyword(s):  
Lattice Dynamics ◽  
Face Centered Cubic ◽  
Cubic Metals ◽  
Face Centered

A Study of the Variation of Monovacancy Formation Energy with the Parameter of Ashcroft's Potential and Different Exchange and Correlation Functions for Some Group-IIa and Group-VIII FCC Metals in the Active Divalent State

2009 ◽  
Vol 293 ◽  
pp. 11-18 ◽  
Author(s):  
Amitava Ghorai
Keyword(s):  
Correlation Functions ◽  
Formation Energy ◽  
Model Potential ◽  
Slight Variation ◽  
Face Centered Cubic ◽  
Group Viii ◽  
Fcc Metals ◽  
Cubic Metals ◽  
Face Centered ◽  
Exchange And Correlation

Graphs of monovacancy formation energy ( ) versus the parameter, , of Ashcroft's empty-core model potential (AECMP) and nine different exchange and correlation functions (ECF) are shown for two different group-IIa divalent fcc metals (Ca and Sr) and seven group-VIII divalent fcc metals in an active valence state (γ-Fe, β-Co, Rh, Ir, Ni, Pd and Pt). The criterion used is that is greater than the Bohr radius. There is a systematic increase and decrease in the fitted value of , and the calculated value of , respectively, in going from one ECF to other, as follows: Sham<K-K<G-V<Kle<Harr<V-S<Hub<Tay<M-D for group-IIa face-centered cubic metals and K-K<G-V<Sham<…..<Tay<Hub<M-D for group-VIII face-centered cubic metals; with a slight variation in between. It should be noted that the inherent simplicity of AECMP makes it difficult to have a universal parameter for all types of atomic property calculations.

Investigating the Plastic Behavior in Face-Centered Cubic Metals with Strain Rate Jumps

2016 ◽  
Vol 683 ◽  
pp. 100-105
Author(s):  
Mikhail Semenov ◽  
Lev Bulygin
Keyword(s):  
Mathematical Model ◽  
Strain Rate ◽  
Microstructure Evolution ◽  
Plastic Behavior ◽  
Face Centered Cubic ◽  
Material Microstructure ◽  
Fcc Metals ◽  
Cubic Metals ◽  
History Of ◽  
Face Centered

History of loading is the result of interaction of the material microstructure evolution and the loading conditions. The present work aims at an investigation of the behavior in face-centered cubic (FCC) metals under loading with a strain rate jump at different stages. In order to describe the behavior of FCC metals under loading we propose a mathematical model. This model is based on a system of ordinary differential equations (ODEs) and realized as software.

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.

A Study on the Uniaxial Tension of FCC Metals at Nano Level Using MD

2008 ◽  
Vol 32 ◽  
pp. 255-258
Author(s):  
Bohayra Mortazavi ◽  
Akbar Afaghi Khatibi
Keyword(s):  
Molecular Dynamics ◽  
Uniaxial Tension ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Face Centered Cubic ◽  
Engineering Strain ◽  
Fcc Metals ◽  
Engineering Stress ◽  
Nano Science ◽  
Face Centered

Molecular Dynamics (MD) are now having orthodox means for simulation of matter in nano-scale. It can be regarded as an accurate alternative for experimental work in nano-science. In this paper, Molecular Dynamics simulation of uniaxial tension of some face centered cubic (FCC) metals (namely Au, Ag, Cu and Ni) at nano-level have been carried out. Sutton-Chen potential functions and velocity Verlet formulation of Noise-Hoover dynamic as well as periodic boundary conditions were applied. MD simulations at different loading rates and temperatures were conducted, and it was concluded that by increasing the temperature, maximum engineering stress decreases while engineering strain at failure is increasing. On the other hand, by increasing the loading rate both maximum engineering stress and strain at failure are increasing.

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