First Principle Study for the Melting Properties of Face-Centred-Cubic Aluminum

2013 ◽  
Vol 535-536 ◽  
pp. 342-345
Author(s):  
Lin Zhou ◽  
Qing Ming Zhang ◽  
Guang Fu Ji ◽  
Zi Zheng Gong
Keyword(s):  
Diamond Anvil Cell ◽  
Melting Curve ◽  
Structure Optimization ◽  
Debye Model ◽  
First Principle ◽  
Static Calculation ◽  
Different Temperatures ◽  
Diamond Anvil ◽  
Melting Properties ◽  
Good Agreement

Ab initio electronic structure optimization and total energy calculations for fcc aluminum are used to study the equation of state (EOS).Through fitting to quasi-harmonic Debye model, the thermodynamics properties of different temperatures are calculated. The melting curve at different pressures is presented based on Lindemann measures. The results show that the calculated EOS and the revised melting curve both are in a good agreement with the shock compression and the diamond-anvil-cell (DAC) data. The results illustrate that we can use simple static calculation method which takes less time to gain reasonable melting results. It can be used in the qualitative forecast for materials with difficult experiments.

scholarly journals On the Jumps of Volume, Enthalpy and Entropy at the Melting Point, the Thermal Conductivity and Thermal Diffusivity for F.C.C. Au: the Temperature- and Pressure-Dependences

2021 ◽  
Vol 22 (4) ◽  
pp. 511-530
Author(s):  
Nguyen Quang  Hoc ◽  
Bui Duc  Tinh ◽  
Nguyen Duc  Hien ◽  
Le Hong  Viet
Keyword(s):  
Thermal Conductivity ◽  
Thermal Diffusivity ◽  
Melting Point ◽  
Melting Curve ◽  
Debye Model ◽  
High Temperature And Pressure ◽  
Enthalpy And Entropy ◽  
Temperature And Pressure ◽  
Limiting Condition ◽  
Good Agreement

The melting temperature, the jumps of volume, enthalpy and entropy at the melting point, the isothermal compressibility, the thermal expansion coefficient, the heat capacity at constant volume, the Grüneisen parameter, the Debye temperature, the electrical resistivity, the thermal conductivity, and the thermal diffusivity for defective and perfect f.c.c. metals are studied by combining the statistical moment method (SMM), the limiting condition of the absolute stability of the crystalline state, the Clapeyron–Clausius equation, the Debye model, the Grüneisen equation, the Wiedemann–Franz law, and the Mott equation. Numerical calculations are carried out for Au under high temperature and pressure. The calculated melting curve of Au is in good agreement with experiments and other calculations. Obtained results are predictive and orient towards new experiments.

High-pressure single-crystal study on AlPO4 with synchrotron radiation

1990 ◽  
Vol 23 (5) ◽  
pp. 397-400 ◽  
Author(s):  
H. Sowa ◽  
K. Reithmayer ◽  
J. Macavei ◽  
W. Rieck ◽  
H. Schulz ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Single Crystal ◽  
Diamond Anvil Cell ◽  
Structural Parameters ◽  
X Rays ◽  
X Ray ◽  
Single Crystal Study ◽  
Diamond Anvil ◽  
Counting Statistics ◽  
Good Agreement

A single-crystal study on AlPO4 was performed at 2.90 (7) GPa with synchrotron radiation using a diamond-anvil cell with a beryllium gasket. For the data collection the radiation wavelength of only 0.54 Å, was chosen to minimize the absorption of X-rays in the pressure cell. The diffracted intensity was high enough to measure even weak reflections with sufficient counting statistics. The refined structural parameters are in good agreement with those determined from data collected with a conventional X-ray tube.

Probing of Structure Factor of Water to 57 GPa and 1500 K

2006 ◽  
Vol 987 ◽  
Author(s):  
Alexander F. Goncharov ◽  
Chrystele Sanloup ◽  
Nir Goldman ◽  
Jonathan C. Crowhurst ◽  
Lawrence E. Fried ◽  
...  
Keyword(s):  
Structure Factor ◽  
Diamond Anvil Cell ◽  
Melting Line ◽  
X Ray ◽  
Structure Factors ◽  
Diamond Anvil ◽  
Laser Heated ◽  
Density Of Water ◽  
Monochromatic Synchrotron ◽  
Good Agreement

AbstractThe x-ray structure factor of water has been measured along the melting line to 57 GPa and 1500 K using focused monochromatic synchrotron radiation and laser heated diamond anvil cell. The oxygen radial distribution function, g(r) is determined from these data. We have also calculated g(r) using ab initio methods and find a good agreement with the experiment. Based of the similarity of the measured and calculated structure factors determined density of water under extreme conditions unattainable previously.

scholarly journals The Bridgmanite–Akimotoite–Majorite Triple Point Determined in Large Volume Press and Laser-Heated Diamond Anvil Cell

Minerals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 67
Author(s):  
Britany L. Kulka ◽  
Jonathan D. Dolinschi ◽  
Kurt D. Leinenweber ◽  
Vitali B. Prakapenka ◽  
Sang-Heon Shim
Keyword(s):  
High Pressure ◽  
Triple Point ◽  
Large Volume ◽  
Diamond Anvil Cell ◽  
Experimental Methods ◽  
Diamond Anvil ◽  
Laser Heated ◽  
Good Agreement

The bridgmanite–akimotoite–majorite (Bm–Ak–Mj or BAM) triple point in MgSiO3 has been measured in large-volume press (LVP; COMPRES 8/3 assembly) and laser-heated diamond anvil cell (LHDAC). For the LVP data, we calculated pressures from the calibration provided for the assembly. For the LHDAC data, we conducted in situ determination of pressure at high temperature using the Pt scale at synchrotron. The measured temperatures of the triple point are in good agreement between LVP and LHDAC at 1990–2000 K. However, the pressure for the triple point determined from the LVP is 3.9 ± 0.6 GPa lower than that from the LHDAC dataset. The BAM triple point determined through these experiments will provide an important reference point in the pressure–temperature space for future high-pressure experiments and will allow mineral physicists to compare the pressure–temperature conditions measured in these two different experimental methods.

scholarly journals The Akimotoite--Majorite--Bridgmanite Triple Point Determined in Large Volume Press and Laser-Heated Diamond Anvil Cell

2019 ◽  
Author(s):  
Britany Kulka ◽  
Jonathan Dolinschi ◽  
Kurt Leinenweber ◽  
Vitali Prakapenka ◽  
Sang-Heon Shim
Keyword(s):  
High Pressure ◽  
Triple Point ◽  
Large Volume ◽  
Diamond Anvil Cell ◽  
Experimental Methods ◽  
Diamond Anvil ◽  
Laser Heated ◽  
Good Agreement

The akimotoite--majorite--bridgmanite (Ak--Mj--Bm) triple point in MgSiO3 has been measured in large-volume press (LVP; COMPRES 8/3 assembly) and laser-heated diamond anvil cell (LHDAC). For the LVP data, we calculated pressures from the calibration by Leinenweber (2012). For the LHDAC data, we conducted \textit{in situ} determination of pressure at high temperature using the Pt scale by Dorogokupets and Dewaele (2007) at synchrotron. The measured temperatures of the triple point are in good agreement between LVP and LHDAC at 1990-2000 K. However, the pressure for the triple point determined from the LVP is 3.9+/-0.6~GPa lower than that from the LHDAC dataset. The triple point determined through these experiments will provide an important reference point in the pressure-temperature space for future high-pressure experiments and allow mineral physicists to compare the pressure--temperature conditions measured in these two different experimental methods.

MELTING CURVE OF WATER STUDIED IN EXTERNALLY HEATED DIAMOND-ANVIL CELL

2003 ◽  
Vol 23 (3) ◽  
pp. 307-311 ◽  
Author(s):  
Natalia Dubrovinskaia ◽  
Leonid Dubrovinsky
Keyword(s):  
Diamond Anvil Cell ◽  
Melting Curve ◽  
Diamond Anvil

scholarly journals Pressure effect of the mechanical, electronics and thermodynamic properties of Mg–B compounds A first-principles investigations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
GuoWei Zhang ◽  
Chao Xu ◽  
MingJie Wang ◽  
Ying Dong ◽  
FengEr Sun ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
First Principles ◽  
Boron Content ◽  
Structural Parameters ◽  
Debye Model ◽  
Total Density ◽  
First Principle ◽  
Volume Deformation ◽  
Temperature And Pressure ◽  
Total Density Of States

AbstractFirst principle calculations were performed to investigate the structural, mechanical, electronic properties, and thermodynamic properties of three binary Mg–B compounds under pressure, by using the first principle method. The results implied that the structural parameters and the mechanical properties of the Mg–B compounds without pressure are well matched with the obtainable theoretically simulated values and experimental data. The obtained pressure–volume and energy–volume revealed that the three Mg–B compounds were mechanically stable, and the volume variation decreases with an increase in the boron content. The shear and volume deformation resistance indicated that the elastic constant Cij and bulk modulus B increased when the pressure increased up to 40 GPa, and that MgB7 had the strongest capacity to resist shear and volume deformation at zero pressure, which indicated the highest hardness. Meanwhile, MgB4 exhibited a ductility transformation behaviour at 30 GPa, and MgB2 and MgB7 displayed a brittle nature under all the considered pressure conditions. The anisotropy of the three Mg–B compounds under pressure were arranged as follows: MgB4 > MgB2 > MgB7. Moreover, the total density of states varied slightly and decreased with an increase in the pressure. The Debye temperature ΘD of the Mg–B compounds gradually increased with an increase in the pressure and the boron content. The temperature and pressure dependence of the heat capacity and the thermal expansion coefficient α were both obtained on the basis of Debye model under increased pressure from 0 to 40 GPa and increased temperatures. This paper brings a convenient understanding of the magnesium–boron alloys.

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