Bond equilibrium theory for Te-rich liquid Tl–Te alloys

1977 ◽  
Vol 55 (11) ◽  
pp. 1930-1936 ◽  
Author(s):  
Melvin Cutler
Keyword(s):  
Free Energy ◽  
Good Description ◽  
Hole Concentration ◽  
Enthalpy Of Mixing ◽  
Dangling Bond ◽  
Fermi Model ◽  
Bond Model ◽  
Independent Information ◽  
Molecular Bond ◽  
Rich Liquid

Recent work has provided independent information about the behavior of the hole concentration c in TlxTe1−x as a function of temperature T and composition x in the range 0.2 ≤ x ≤ 0.6. This makes possible a critical reexamination of a molecular bond model for the structure of the alloy, in which holes are generated by broken Te—Te bonds. The earlier theory is revised to formulate an unrestricted independent bond model (ibm), for which the equations are simple and have obvious physical interpretations. This provides a good description of c(T) but only a qualitatively correct c(x). Using a Thomas–Fermi model for the screening interaction between holes and the acceptor ions, it is shown that the equilibrium constant can be expected to increase rapidly with c at large enough values. A modification in which the free energy of a dangling bond is decreased by proximity to a Tl—Te bond is found to significantly improve the result for c(x). The thermochemical behavior is derived. The entropy of mixing is in fair agreement with experiment, but the enthalpy of mixing is grossly wrong. This reflects the neglect of intermolecular interactions in the theory, which, it seems, can easily account for the remaining discrepancies in the predicted behavior of c.

Charge-Defect Equilibrium Description of the Staebler-Wronski Defect Concentration and Formation Energy

1991 ◽  
Vol 219 ◽  
Author(s):  
C. M. Fortmann ◽  
R. M. Dawson ◽  
C. R. Wronski
Keyword(s):  
Free Energy ◽  
High Temperature ◽  
Amorphous Materials ◽  
Structural Changes ◽  
Energy State ◽  
Bond Formation ◽  
Free Energy Change ◽  
Energy Change ◽  
Dangling Bond ◽  
Charge Defect

ABSTRACTAn equilibrium framework for the high temperature behavior of dangling bond defects in amorphous materials is developed. With this framework it is possible to relate the thermal formation of defects directly with those created by high temperature illumination or current injection. It is found that the free energy change associated with dangling bond formation is negative. The negative free energy change means that if one considered only the structural changes, the lowest energy state for the system is with the weak bonds split into neutral and charged dangling bonds!

Application of Solid Phase Epitaxy for Measuring Dangling Bond Densities and Impurity Ionization in Amorphous Silicon

1990 ◽  
Vol 205 ◽  
Author(s):  
R. M. Walser ◽  
Young-Jin Jeon
Keyword(s):  
Amorphous Silicon ◽  
Solid Phase ◽  
Recent Model ◽  
Solid Phase Epitaxy ◽  
Dangling Bond ◽  
Bond Model ◽  
Low Concentrations ◽  
Impurity Ionization ◽  
Considerable Support ◽  
Good Agreement

AbstractAccording to a recent model [1], the enhancement in the rate of the solid phase epitaxial regrowth (SPER) of silicon produced by implanted impurities is determined by the superposition of reconstruction at sites that capture neutral, and ionized, three-fold coordinated dangling bond states. Considerable support for this model is derived from experiments on ionization-enhanced SPER in silicon. In this paper we discuss how this dangling bond model (DBM) could be used to determine the densities of neutral dangling bonds and ionized impurities in amorphous silicon from these experimental results. Both densities, determined by a self-consistent calculation, are in good agreement with those measured by other types of experiments. This result provides further support for the DBM and indicates that simultaneous SPER and ESR measurements could make it possible to depth profile low concentrations of ionized impurities in amorphous silicon.

scholarly journals Effect of temperature on mixing behavior and stability of liquid Al-Fe alloys

2021 ◽  
Vol 2070 (1) ◽  
pp. 012025
Author(s):  
I B Bhandari ◽  
N Panthi ◽  
S Gaire ◽  
Ishwar Koirala
Keyword(s):  
Free Energy ◽  
Surface Composition ◽  
Dynamic Properties ◽  
Enthalpy Of Mixing ◽  
Effect Of Temperature ◽  
Mixing Enthalpy ◽  
Energy Parameters ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing ◽  
Experimental Values

Abstract A theoretical model based on the assumption of compound formation in binary liquid alloy has been used to investigate the thermodynamic properties (free energy of mixing, enthalpy of mixing and entropy of mixing), microscopic properties (concentration fluctuation in long wavelength limit and chemical short range order parameter), surface properties (surface tension and surface composition) and dynamic properties ( viscosity and diffusion coefficient). All the properties of Al2Fe binary melt have been measured using the same energy parameters configured for experimental values of free energy of mixing. The energy parameters are detected as independent of concentration, but depend on temperature. The findings are well consistent with the experimental standards.

Wandering Dangling Bond Model for Staebler-Wronski Effects

1998 ◽  
Vol 507 ◽  
Author(s):  
Masatoshi Ikeda ◽  
Akio Kitagawa ◽  
Masakuni Suzuki
Keyword(s):  
Rate Equations ◽  
Dangling Bond ◽  
Dangling Bonds ◽  
Covalent Bonds ◽  
New Model ◽  
Bond Model ◽  
Annealing Effects

ABSTRACTA new model for Staebler-Wronski effects is proposed. Defect pairs of (D°:D+) or (D°:D°) as a precursor of neutral dangling bonds are produced by electron-phonon interactions. Most of the defect-pairs immediately rebond after creation, but some of them separate resulting in wandering dangling bonds. The separation and the wandering take place through bond-switching. When wandering dangling bonds collide, most of them make covalent bonds via defect-pairs. The rate equations based on these processes are given and annealing effects on photo-generated dangling bonds are studied.

Liquidus Curves of Eutectic NaK and NaCs Systems

1984 ◽  
Vol 39 (9) ◽  
pp. 842-845 ◽  
Author(s):  
L. J. Gallego ◽  
J. M. López ◽  
J. A. Alonso
Keyword(s):  
Free Energy ◽  
Cell Surface ◽  
Enthalpy Of Mixing ◽  
Semiempirical Model ◽  
Binary Liquid ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing ◽  
Modified Forms ◽  
Atomic Cell ◽  
Surface Area Concentration

The Conformal Solution and Flory's expressions for the free energy of mixing ΔGM of a binary liquid alloy have been modified by using a form for the enthalpy of mixing ΔHM which incorporates the concentration dependence given by Miedema's semiempirical model. This model emphasizes the importance of the atomic cell-surface area concentration in evaluating ΔHM. The modified forms of ΔGM have been used to construct the liquidus curves of NaCs and NaK.

NEUTRON MATTER PROPERTIES USING GENERALIZED SKYRME FORCE

2002 ◽  
Vol 11 (05) ◽  
pp. 445-454
Author(s):  
H. M. M. MANSOUR ◽  
KH. A. RAMADAN
Keyword(s):  
Free Energy ◽  
Magnetic Susceptibility ◽  
Binding Energy ◽  
Symmetry Energy ◽  
Body Force ◽  
Spin Symmetry ◽  
Skyrme Force ◽  
Neutron Matter ◽  
Fermi Model ◽  
Three Body

The generalized Skyrme potential is used to calculate the properties of neutron matter in the form of the Thomas–Fermi model. The binding energy per particle, spin symmetry energy, free energy, pressure, entropy, sound velocity and magnetic susceptibility are calculated as a function of density ρ. The results are comparable with those obtained by Friedman and Pandharipande, who used the Urbana v14 potential plus an effective repulsive three-body force.

Computer Simulation of Electron Spin Resonance Spectra of Ge25S75and Ge30S70 Bulk Glasses

1997 ◽  
Vol 62 (11) ◽  
pp. 1721-1729
Author(s):  
Zdeněk Černošek ◽  
Marek Liška ◽  
Peter Pelikán ◽  
Eva Černošková ◽  
Marián Valko ◽  
...  
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Liquid Nitrogen Temperature ◽  
Esr Spectra ◽  
Dangling Bond ◽  
Paramagnetic Defect ◽  
Bond Model ◽  
Spin Resonance ◽  
Bulk Glasses ◽  
Good Agreement

The electron spin resonance (ESR) spectra of bulk glasses of the chemical composition Ge25S75 and Ge30S70 were measured at liquid nitrogen temperature and subjected to computerized separation. The complex ESR spectra of both glasses were found to represent a superposition of three paramagnetic defect spectra, two with orthorhombic tensors g and one with the axial tensor g. The former two paramagnetic centers can be related to a two-atomic defect of the sulfur-sulfur type, the latter to a germanium-sulfur defect. The experimental results are in a good agreement with the non-dangling bond model of paramagnetic defects in Ge-S glasses.

PHASE DIAGRAM OF THE THREE DIMENSIONAL FOUR FERMI MODEL WITH FINITE N CORRECTIONS

2007 ◽  
Vol 16 (09) ◽  
pp. 2802-2805 ◽  
Author(s):  
JEAN-LOÏC KNEUR ◽  
MARCUS BENGHI PINTO ◽  
RUDNEI O. RAMOS ◽  
EDERSON STAUDT
Keyword(s):  
Phase Diagram ◽  
Free Energy ◽  
Perturbation Theory ◽  
Finite Temperature ◽  
Chemical Potential ◽  
Three Dimensional ◽  
Fermi Model ◽  
Analytical Results ◽  
Theory Technique ◽  
Gross Neveu Model

We study the phase diagram of the 3d massless Gross–Neveu model with different numbers of fermionic species, N. Using the Optimized Perturbation Theory technique, the free energy is evaluated at finite temperature and chemical potential. The analytical results allow us to calculate critical quantities for any value of N and, in the present work, we choose de values N = 1,3,4,10. In addition, we determine the evolution of the tricritical points, in the temperature versus chemical potential plane for these different values of N.

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