Molecular dynamics modeling of stishovite

Luo, Sheng‐Nian; Çağın, Tahir; Strachan, Alejandro; Goddard, William A.; Ahrens, Thomas J.

doi:10.1016/s0012-821x(02)00749-5

Cited by 22 publications

(24 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this work, we conducted single-and two-phase simulations of the melting and refreezing of close-packed metals. These simulations along with previous work 13,34,35 allow us to systematically examine superheating and undercooling behavior for elements and compounds described with different potentials against the maximum superheating-undercooling systematics developed. The pressure effect on superheating is also addressed.…”

Section: Molecular Dynamics Simulations Of Maximum Superheating mentioning

confidence: 96%

“…For silica's high-pressure phase stishovite with a Morse-stretch-charge-equilibrium FF, ⌰ md ϩ ϭ0.28 was achieved at 120 GPa. 13 The comparison above between MD simulations and the predictions of the superheating-undercooling systematics assumed that the force fields utilized in MD simulations accurately describe real systems; this is not necessarily the case. The equilibrium melting temperature from MD simulations (T 2,m ) deviates from the experimental counterpart (T e,m ) at ambient pressure for some metals ͑Table V͒.…”

Section: Molecular Dynamics Simulations Of Maximum Superheating mentioning

confidence: 99%

“…It has long been recognized that temperature hysteresis exists in MD simulations of bulk crystal with threedimensional ͑3D͒ periodic boundaries. [9][10][11][12][13] But a systematic and quantitative investigation of both superheating and un-dercooling in MD simulations has not been previously conducted. It is of particular interest whether consistent predictions of both superheating and undercooling and also material properties can be made using a single set of force fields in MD simulations.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Maximum superheating and undercooling: Systematics, molecular dynamics simulations, and dynamic experiments

et al. 2003

Self Cite

View full text Add to dashboard Cite

The maximum superheating and undercooling achievable at various heating ͑or cooling͒ rates were investigated based on classical nucleation theory and undercooling experiments, molecular dynamics ͑MD͒ simulations, and dynamic experiments. The highest ͑or lowest͒ temperature T c achievable in a superheated solid ͑or an undercooled liquid͒ depends on a dimensionless nucleation barrier parameter ␤ and the heating ͑or cooling͒ rate Q. ␤ depends on the material: ␤ϵ16␥ sl 3 /(3kT m ⌬H m 2 ) where ␥ sl is the solid-liquid interfacial energy, ⌬H m the heat of fusion, T m the melting temperature, and k Boltzmann's constant. The systematics of maximum superheating and undercooling were established phenomenologically as ␤ϭ(A 0 Ϫb log 10 Q) c (1Ϫ c ) 2 where c ϭT c /T m , A 0 ϭ59.4, bϭ2.33, and Q is normalized by 1 K/s. For a number of elements and compounds, ␤ varies in the range 0.2-8.2, corresponding to maximum superheating c of 1.06 -1.35 and 1.08 -1.43 at Q ϳ1 and 10 12 K/s, respectively. Such systematics predict that a liquid with certain ␤ cannot crystallize at cooling rates higher than a critical value and that the smallest c achievable is 1/3. MD simulations (Q ϳ10 12 K/s) at ambient and high pressures were conducted on close-packed bulk metals with Sutton-Chen many-body potentials. The maximum superheating and undercooling resolved from single-and two-phase simulations are consistent with the c -␤-Q systematics for the maximum superheating and undercooling. The systematics are also in accord with previous MD melting simulations on other materials ͑e.g., silica, Ta and ⑀-Fe͒ described by different force fields such as Morse-stretch charge equilibrium and embedded-atom-method potentials. Thus, the c -␤-Q systematics are supported by simulations at the level of interatomic interactions. The heating rate is crucial to achieving significant superheating experimentally. We demonstrate that the amount of superheating achieved in dynamic experiments (Qϳ10 12 K/s), such as planar shock-wave loading and intense laser irradiation, agrees with the superheating systematics.

show abstract

Section: Molecular Dynamics Simulations Of Maximum Superheating mentioning

confidence: 96%

Section: Molecular Dynamics Simulations Of Maximum Superheating mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Maximum superheating and undercooling: Systematics, molecular dynamics simulations, and dynamic experiments

et al. 2003

Self Cite

View full text Add to dashboard Cite

show abstract

“…They carried out simulations over a wide range of pressure (from 0 to 150 GPa) and temperature (3 000-6 000 K) but analyzed compression effects under constant temperature. Most temperatures considered were distinctly lower than the melting temperatures (Luo et al, 2005;Belonoshko and Dubrovinsky, 1995), indicating that they simulated supercooling liquids out of the thermodynamic stability of melt. Such a state likely appears in a short simulation time and is thus unrealistic to discuss actually physical properties of melt.…”

Section: Introductionmentioning

confidence: 96%

“…The interface assists in the nucleation and growth for the melting or the solidification process. Two TP-MD simulations of stishovite+liquid have been performed previously (Luo et al, 2005;Belonoshko and Dubrovinsky, 1995). However, since these studies used the classical MD methods based on the semiempirical interatomic potential, the reliability of the simulated melting temperature especially under high-pressure conditions are likely relatively low.…”

Section: Introductionmentioning

confidence: 99%

Ab initio two-phase molecular dynamics on the melting curve of SiO2

Usui¹,

Tsuchiya²

2010

J. Earth Sci.

View full text Add to dashboard Cite

Ab initio two-phase molecular dynamics simulations were performed on silica at pressures of 20-160 GPa and temperatures of 2 500-6 000 K to examine its solid-liquid phase boundary.Results indicate a melting temperature (T m ) of 5 900 K at 135 GPa. This is 1 100 K higher than the temperature considered for the core-mantle boundary (CMB) of about 3 800 K. The calculated melting temperature is fairly consistent with classical MD (molecular dynamics) simulations. For liquid silica, the O-O coordination number is found to be 12 along the T m and is almost unchanged with increasing pressure. The self-diffusion coefficients of O and Si atoms are determined to be 1.3×10 -9 -3.3×10 -9 m 2 /s, and the viscosity is 0.02-0.03 Pa·s along the T m . We find that these transport properties depend less on pressure in the wide range up of more than 135 GPa. The eutectic temperatures in the MgO-SiO 2 systems were evaluated and found to be 700 K higher than the CMB temperature, though they would decrease considerably in more realistic mantle compositions.

show abstract

High‐pressure, high‐temperature equations of state using nanofabricated controlled‐geometry Ni/SiO₂/Ni double hot‐plate samples

Pigott

Ditmer²,

Fischer

et al. 2015

Geophysical Research Letters

View full text Add to dashboard Cite

We have fabricated novel controlled‐geometry samples for the laser‐heated diamond‐anvil cell (LHDAC) in which a transparent oxide layer (SiO2) is sandwiched between two laser‐absorbing layers (Ni) in a single, cohesive sample. The samples were mass manufactured (>104 samples) using a combination of physical vapor deposition, photolithography, and wet and plasma etching. The double hot‐plate arrangement of the samples, coupled with the chemical and spatial homogeneity of the laser‐absorbing layers, addresses problems of spatial temperature heterogeneities encountered in previous studies where simple mechanical mixtures of transparent and opaque materials were used. Here we report thermal equations of state (EOS) for nickel to 100 GPa and 3000 K and stishovite to 50 GPa and 2400 K obtained using the LHDAC and in situ synchrotron X‐ray microdiffraction. We discuss the inner core composition and the stagnation of subducted slabs in the mantle based on our refined thermal EOS.

show abstract

Molecular dynamics modeling of stishovite

Cited by 22 publications

References 37 publications

Maximum superheating and undercooling: Systematics, molecular dynamics simulations, and dynamic experiments

Maximum superheating and undercooling: Systematics, molecular dynamics simulations, and dynamic experiments

Ab initio two-phase molecular dynamics on the melting curve of SiO2

High‐pressure, high‐temperature equations of state using nanofabricated controlled‐geometry Ni/SiO₂/Ni double hot‐plate samples

Contact Info

Product

Resources

About

Molecular dynamics modeling of stishovite

Cited by 22 publications

References 37 publications

Maximum superheating and undercooling: Systematics, molecular dynamics simulations, and dynamic experiments

Maximum superheating and undercooling: Systematics, molecular dynamics simulations, and dynamic experiments

Ab initio two-phase molecular dynamics on the melting curve of SiO2

High‐pressure, high‐temperature equations of state using nanofabricated controlled‐geometry Ni/SiO2/Ni double hot‐plate samples

Contact Info

Product

Resources

About

High‐pressure, high‐temperature equations of state using nanofabricated controlled‐geometry Ni/SiO₂/Ni double hot‐plate samples