The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
Sergei I Simak - One of the best experts on this subject based on the ideXlab platform.
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systematics of the third row transition Metal Melting the hcp Metals rhenium and osmium
Crystals, 2018Co-Authors: L Burakovsky, Naftali Burakovsky, Dean L Preston, Sergei I SimakAbstract:The Melting curves of rhenium and osmium to megabar pressures are obtained from an extensive suite of ab initio quantum molecular dynamics (QMD) simulations using the Z method. In addition, for Re, we combine QMD simulations with total free energy calculations to obtain its phase diagram. Our results indicate that Re, which generally assumes a hexagonal close-packed (hcp) structure, melts from a face-centered cubic (fcc) structure in the pressure range 20–240 GPa. We conclude that the recent DAC data on Re to 50 GPa in fact encompass both the true Melting curve and the low-slope hcp-fcc phase boundary above a triple point at (20 GPa, 4240 K). A linear fit to the Re diamond anvil cell (DAC) data then results in a slope that is 2.3 times smaller than that of the actual Melting curve. The phase diagram of Re is topologically equivalent to that of Pt calculated by us earlier on. Regularities in the Melting curves of Re, Os, and five other 3rd-row transition Metals (Ta, W, Ir, Pt, Au) form the 3rd-row transition Metal Melting systematics. We demonstrate how this systematics can be used to estimate the currently unknown Melting curve of the eighth 3rd-row transition Metal Hf.
L Burakovsky - One of the best experts on this subject based on the ideXlab platform.
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systematics of the third row transition Metal Melting the hcp Metals rhenium and osmium
Crystals, 2018Co-Authors: L Burakovsky, Naftali Burakovsky, Dean L Preston, Sergei I SimakAbstract:The Melting curves of rhenium and osmium to megabar pressures are obtained from an extensive suite of ab initio quantum molecular dynamics (QMD) simulations using the Z method. In addition, for Re, we combine QMD simulations with total free energy calculations to obtain its phase diagram. Our results indicate that Re, which generally assumes a hexagonal close-packed (hcp) structure, melts from a face-centered cubic (fcc) structure in the pressure range 20–240 GPa. We conclude that the recent DAC data on Re to 50 GPa in fact encompass both the true Melting curve and the low-slope hcp-fcc phase boundary above a triple point at (20 GPa, 4240 K). A linear fit to the Re diamond anvil cell (DAC) data then results in a slope that is 2.3 times smaller than that of the actual Melting curve. The phase diagram of Re is topologically equivalent to that of Pt calculated by us earlier on. Regularities in the Melting curves of Re, Os, and five other 3rd-row transition Metals (Ta, W, Ir, Pt, Au) form the 3rd-row transition Metal Melting systematics. We demonstrate how this systematics can be used to estimate the currently unknown Melting curve of the eighth 3rd-row transition Metal Hf.
Marvin Ross - One of the best experts on this subject based on the ideXlab platform.
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Systematics of transition-Metal Melting
Physical Review B, 2001Co-Authors: Daniel Errandonea, Beate Schwager, Reiner Ditz, Christine H. Gessmann, Reinhard Boehler, Marvin RossAbstract:We report high-pressure measurements for the Melting curve of Ti, V, Cr, Mo, Ta, W, Fe, Co, and Ni. Measurements were made in a laser-heated diamond-anvil-cell to nearly 100 GPa and 4000 K. The bcc Metals have surprisingly small Melting slopes which approach zero at high pressure. The Melting curves of Co, Ni, and Fe are nearly parallel. Several ab-initio calculations for the Melting of Fe are incompatible with the present results.
Naftali Burakovsky - One of the best experts on this subject based on the ideXlab platform.
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systematics of the third row transition Metal Melting the hcp Metals rhenium and osmium
Crystals, 2018Co-Authors: L Burakovsky, Naftali Burakovsky, Dean L Preston, Sergei I SimakAbstract:The Melting curves of rhenium and osmium to megabar pressures are obtained from an extensive suite of ab initio quantum molecular dynamics (QMD) simulations using the Z method. In addition, for Re, we combine QMD simulations with total free energy calculations to obtain its phase diagram. Our results indicate that Re, which generally assumes a hexagonal close-packed (hcp) structure, melts from a face-centered cubic (fcc) structure in the pressure range 20–240 GPa. We conclude that the recent DAC data on Re to 50 GPa in fact encompass both the true Melting curve and the low-slope hcp-fcc phase boundary above a triple point at (20 GPa, 4240 K). A linear fit to the Re diamond anvil cell (DAC) data then results in a slope that is 2.3 times smaller than that of the actual Melting curve. The phase diagram of Re is topologically equivalent to that of Pt calculated by us earlier on. Regularities in the Melting curves of Re, Os, and five other 3rd-row transition Metals (Ta, W, Ir, Pt, Au) form the 3rd-row transition Metal Melting systematics. We demonstrate how this systematics can be used to estimate the currently unknown Melting curve of the eighth 3rd-row transition Metal Hf.
Dean L Preston - One of the best experts on this subject based on the ideXlab platform.
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systematics of the third row transition Metal Melting the hcp Metals rhenium and osmium
Crystals, 2018Co-Authors: L Burakovsky, Naftali Burakovsky, Dean L Preston, Sergei I SimakAbstract:The Melting curves of rhenium and osmium to megabar pressures are obtained from an extensive suite of ab initio quantum molecular dynamics (QMD) simulations using the Z method. In addition, for Re, we combine QMD simulations with total free energy calculations to obtain its phase diagram. Our results indicate that Re, which generally assumes a hexagonal close-packed (hcp) structure, melts from a face-centered cubic (fcc) structure in the pressure range 20–240 GPa. We conclude that the recent DAC data on Re to 50 GPa in fact encompass both the true Melting curve and the low-slope hcp-fcc phase boundary above a triple point at (20 GPa, 4240 K). A linear fit to the Re diamond anvil cell (DAC) data then results in a slope that is 2.3 times smaller than that of the actual Melting curve. The phase diagram of Re is topologically equivalent to that of Pt calculated by us earlier on. Regularities in the Melting curves of Re, Os, and five other 3rd-row transition Metals (Ta, W, Ir, Pt, Au) form the 3rd-row transition Metal Melting systematics. We demonstrate how this systematics can be used to estimate the currently unknown Melting curve of the eighth 3rd-row transition Metal Hf.