scholarly journals Critical Temperature for Ordered-Disordered Phase Transformation in Cu3Au under Pressure

2018 ◽  
Vol 2018 ◽  
pp. 1-4
Author(s):  
Pham Dinh Tam ◽  
Bui Duc Tinh ◽  
Nguyen Quang Hoc ◽  
Pham Duy Tan
Keyword(s):  
Experimental Data ◽  
Phase Transformation ◽  
Critical Temperature ◽  
Moment Method ◽  
Statistical Moment ◽  
Disordered Phase ◽  
Good Agreement ◽  
Statistical Moment Method

We use the statistical moment method to study the dependence of the critical temperature Tc for Cu3Au on pressure in the interval from 0 to 30 kbar. The calculated mean speed of changing critical temperature to pressure is 1.8 K/kbar. This result is in a good agreement with the experimental data.

Melting curve of metals Cu, Ag and Au under pressure

2016 ◽  
Vol 30 (02) ◽  
pp. 1550273 ◽  
Author(s):  
Pham Dinh Tam ◽  
Nguyen Quang Hoc ◽  
Bui Duc Tinh ◽  
Pham Duy Tan
Keyword(s):  
Experimental Data ◽  
Melting Temperature ◽  
Moment Method ◽  
Melting Curve ◽  
Statistical Moment ◽  
Good Agreement ◽  
Statistical Moment Method

In this paper, the dependence of the melting temperature of metals Cu, Ag and Au under pressure in the interval from 0 kbar to 40 kbar is studied by the statistical moment method (SMM). This dependence has the form of near linearity and the calculated slopes of melting curve are 3.9 for Cu, 5.7 for Ag and 6 for Au. These results are in good agreement with the experimental data.

MELTING CURVE OF SEMICONDUCTORS WITH DEFECTS: PRESSURE DEPENDENCE

2012 ◽  
Vol 26 (07) ◽  
pp. 1250050 ◽  
Author(s):  
VU VAN HUNG ◽  
LE DAI THANH
Keyword(s):  
High Pressure ◽  
Moment Method ◽  
High Pressures ◽  
Melting Curve ◽  
Statistical Moment ◽  
Negative Slope ◽  
Pressure Melting ◽  
New Equation ◽  
Good Agreement ◽  
Statistical Moment Method

The high-pressure melting curve of semiconductors with defects has been studied using statistical moment method (SMM). In agreement with experiments and with DFT calculations we obtain a negative slope for the high-pressure melting curve. We have derived a new equation for the melting curve of the defect semiconductors. The melting was investigated at different high pressures, and the SMM calculated melting temperature of Si, AlP, AlAs and GaP crystals with defects being in good agreement with previous experiments.

THE DIFFUSION IN FCC BINARY INTERSTITIAL ALLOY

2020 ◽  
Vol 65 (10) ◽  
pp. 18-23
Author(s):  
Hoc Nguyen Quang ◽  
Loan Pham Thi Thanh ◽  
Viet Nguyen Tuan ◽  
Le Nguyen Ngoc
Keyword(s):  
Diffusion Coefficient ◽  
Moment Method ◽  
Interstitial Atom ◽  
Diffusion Theory ◽  
Correlation Factor ◽  
Statistical Moment ◽  
Analytic Expressions ◽  
Fcc Metal ◽  
Statistical Moment Method

We build the theory of diffusion for FCC binary interstitial alloy under pressure based on the statistical moment method, where there are the analytic expressions of the jumping frequency of interstitial atom, the effective jumping length, the correlation factor, the diffusion coefficient, and the activated energy. In limit cases, we can obtain the diffusion theory for FCC metal A under pressure.

The use of electron gas modification in the evaluation of the vibration frequencies and the specific heat of lithium

1960 ◽  
Vol 259 (1298) ◽  
pp. 361-369 ◽  
Keyword(s):  
Experimental Data ◽  
Phase Transformation ◽  
Electron Gas ◽  
Vibration Frequencies ◽  
Specific Heats ◽  
Air Temperatures ◽  
Set Up ◽  
Good Agreement ◽  
Secular Determinant

A secular determinant for the determination of vibration frequencies of lithium has been set up by Launay’s method which takes the electron gas into account. Theoretical elastic constants have been used in the calculation of the force constants. Frequencies have been calculated for 47 points of the first Brillouin zone which gives the value of 3 x 1000 = 3000 frequencies by symmetry. Specific heats have been calculated by numerical computation in the range 300 to 6°K and show good agreement with the experimental data. The agreement below liquid-air temperatures is surprising in view of the known phase transformation of lithium.

scholarly journals Studying the Effects of Vacancies on the Melting Temperature of \(\text{AgCe}\) Alloy

2018 ◽  
Vol 28 (2) ◽  
pp. 155
Author(s):  
Dang Thanh Hai ◽  
Vu Van Hung ◽  
Giang Thi Hong
Keyword(s):  
High Pressure ◽  
Free Energy ◽  
Melting Temperature ◽  
Moment Method ◽  
Statistical Moment ◽  
Melting Temperatures ◽  
Substitution Alloy ◽  
Numerical Calculation Method ◽  
Analytical Expressions ◽  
Statistical Moment Method

In order to evaluate the effects of vacancies on the melting temperature of AgCe alloy, the statistical moment method was used to find out the analytical expressions to determine the Gibbs free energy in the AB substitution alloy and the expression to calculate the melting temperature of perfect and imperfect AB substitution Alloys. The melting temperature was calculated by the numerical calculation method on the perfect and imperfect AgCe alloy. The calculating results shown that the melting temperature of alloys increase with a increase in pressure. The melting temperatures of imperfect alloy of AgCe, Ag2Ce and Ag3Ce are always slightly lower than that of perfect alloys. Especially, the melting temperatures value of perfect and imperfect alloy were almost the same at high pressure. The melting temperature of alloys increase with an increase in amount of Ag containing in the alloys. The calculated results agreed well with the experimental results at P = 0.

scholarly journals Investigation of the EXAFS Cumulants of Silicon and Germanium Semiconductors by Statistical Moment Method: Pressure Dependence

2011 ◽  
Vol 21 (3) ◽  
pp. 245
Author(s):  
Ho Khac Hieu ◽  
Vu Van Hung ◽  
Nguyen Van Hung
Keyword(s):  
Pressure Dependence ◽  
Moment Method ◽  
Reasonable Agreement ◽  
Statistical Moment ◽  
X Ray ◽  
Lattice Constants ◽  
Silicon And Germanium ◽  
X Ray Absorption ◽  
Analytical Expressions ◽  
Statistical Moment Method

Pressure dependence of Extended X-ray Absorption Fine Structure (EXAFS) cumulants of silicon and germanium have been investigated using the statistical moment method (SMM). Analytical expressions of the first and second cumulants of silicon and germanium have been derived. The equations of states for silicon and germanium semiconductors have been also obtained using which the pressure dependence of lattice constants and volume of these semiconductors have been estimated. Numerical results using the developed theories for these semiconductors are found to be in good and reasonable agreement with those of the other theories and with experiment.

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