It is argued that the article by O’Bannon et al. “High pressure stability of β-Zr: no evidence fo... more It is argued that the article by O’Bannon et al. “High pressure stability of β-Zr: no evidence for isostructural phase transitions” published recently (July 2021) in High Pressure Research has no experimental foundation and the statement “no evidence” is misleading. The existence of the transitions ω → β → β’ have been experimentally observed by Akahama et al. (2001) DAC experiment using gold PTM. The experiment by E. Stavrou et al. , refined by J. Gal, confirmed cascading transitions ω → β → β’ in compressed Zr metal powder with no PTM (Zr PTM), confirming the isostructural bcc cascade β → β’→ β”. It is demonstrated that the observation of the ω → β → β’ depend on the selected pressure transmitting media used in the DAC. Contrary to O’Bannon et al. article it is concluded that Zr metal, at the pressure range of ~ 30 200 GPa, exhibits a metastable ω phase, which transforms by a first order phase transition to β phase, which then transforms to the β" ground state via the β’ phas...
The solid noble gases Ar, Xe and Kr equations of state and their melting data are fitted by apply... more The solid noble gases Ar, Xe and Kr equations of state and their melting data are fitted by applying Lindemann-Gilvarry criterion.
The pressure–temperature scales in DAC and shock wave (SW) experiments should be corrected by tak... more The pressure–temperature scales in DAC and shock wave (SW) experiments should be corrected by taking into account the thermal pressure shifts. In the present contribution, it is further claimed that first-principle ab initio DFT and MD simulations should serve as an anchor for correcting the pressures and temperatures reported by DAC and SW experiments. It was concluded that upon deriving the actual pressure sensed by the explored sample, the thermal pressure and the temperature shifts must be taken into account when constructing melting curves. Therefore, melting curves measured by diamond anvil cells for 3d elements do not contribute to a better understanding of the geophysical Earth’s inner core. In addition, the advantage of the Lindemann–Gilvarry vs. Simon–Glatzel fitting procedure of melting curves is shown.
It is argued that the article by O’Bannon et al. “High pressure stability of β-Zr: no evidence fo... more It is argued that the article by O’Bannon et al. “High pressure stability of β-Zr: no evidence for isostructural phase transitions” published recently (July 2021) in High Pressure Research has no experimental foundation and the statement “no evidence” is misleading. The existence of the transitions ω → β → β’ have been experimentally observed by Akahama et al. (2001) DAC experiment using gold PTM. The experiment by E. Stavrou et al. , refined by J. Gal, confirmed cascading transitions ω → β → β’ in compressed Zr metal powder with no PTM (Zr PTM), confirming the isostructural bcc cascade β → β’→ β”. It is demonstrated that the observation of the ω → β → β’ depend on the selected pressure transmitting media used in the DAC. Contrary to O’Bannon et al. article it is concluded that Zr metal, at the pressure range of ~ 30 200 GPa, exhibits a metastable ω phase, which transforms by a first order phase transition to β phase, which then transforms to the β" ground state via the β’ phas...
The solid noble gases Ar, Xe and Kr equations of state and their melting data are fitted by apply... more The solid noble gases Ar, Xe and Kr equations of state and their melting data are fitted by applying Lindemann-Gilvarry criterion.
The pressure–temperature scales in DAC and shock wave (SW) experiments should be corrected by tak... more The pressure–temperature scales in DAC and shock wave (SW) experiments should be corrected by taking into account the thermal pressure shifts. In the present contribution, it is further claimed that first-principle ab initio DFT and MD simulations should serve as an anchor for correcting the pressures and temperatures reported by DAC and SW experiments. It was concluded that upon deriving the actual pressure sensed by the explored sample, the thermal pressure and the temperature shifts must be taken into account when constructing melting curves. Therefore, melting curves measured by diamond anvil cells for 3d elements do not contribute to a better understanding of the geophysical Earth’s inner core. In addition, the advantage of the Lindemann–Gilvarry vs. Simon–Glatzel fitting procedure of melting curves is shown.
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Papers by Joseph Gal