EHPRG: The European High Pressure Research Group

## Welcome

Welcome to the official website of the European High Pressure Research Group (EHPRG).

EHPRG is non-profitable academic association established in 1963 which is devoted to science and technology of matter under high pressure. It organizes an annual meeting which brings together hundreds of scientists of various fields, mainly physics, chemistry, Earth and planetary sciences, bio- and food science and technology.

The reasonable size of the group, low conference fees, and a friendly relationship between the attendants have made EHPRG meetings a major event in the European high-pressure community for more than half a century.

## Upcoming high pressure meetings

The current COVID pandemic has led to the cancellation of numerous scientific conferences over the last year, including the 2020 GRC and GRS high-pressure conferences, and the combined AIRAPT/EHPRG-2021 conference that was to be held in Edinburgh this summer. The negative effects of this are being most keenly felt by younger researchers, who have missed golden opportunities to present both their work, and themselves, to the rest of the community.
This online conference aims to address this, by providing up to 360 20-minute oral presentations in which young and early career researchers in our field to present their research to the rest of our international community. Such researchers will be offered the great majority of these slots, complemented by some didactic talks from more established researchers and facility operators. Everyone in the high-pressure community is welcome to attend.
CESC-2021 will be chaired by Malcolm McMahon.
For more information, please visit the official webpage of CSEC2021.

## Upcoming EHPRG Meeting

The Joint 28th AIRAPT and 60th EHPRG International Conference on High Pressure Science and Technology (AIRAPT-2021), originally scheduled for July 2021, has been postponed, and will be held in Edinburgh, UK, in 2023. Exact dates will be announced as soon as possible. AIRAPT-21 will be chaired by Malcolm McMahon (CSEC and University of Edinburgh, UK).
In spite of the Joint AIRAPT-EHPRG Conference, an online Conference on Science at Extreme Conditions will take place in 2021. This online event will have a special focus on young and early career researchers. This will NOT be an AIRAPT/EHPRG conference, but the organizers expect to be able to offer up to 360 slots for 20-minute, and 5-minute “lightning”, oral presentations, spread over 5 days, each of which will have two 2-hour time slots (11am-1pm and 3-5pm UK time), timed so as to provide “office hours” access to speakers from Asia/Europe and Americas/Europe, respectively. Each 2-hour time slot will host up to 6 parallel sessions. The great majority of the available slots for talks will be given to young researchers, complemented by some didactic presentations from more established researchers and facility providers. Everyone in the high-pressure community is welcome to attend.
For more information, please visit the official webpage of AIRAPT-21.

## High-pressure in the headlines

Selection of high-pressure related titles from top scientific journals.

Rates of protoplanetary accretion and differentiation set nitrogen budget of rocky planets
by Damanveer S. Grewal

Nature Geoscience, Published online: 10 May 2021; doi:10.1038/s41561-021-00733-0

Rates of protoplanetary accretion and differentiation control the depletion of nitrogen in rocky planets, according to high-pressure/temperature experiments that show that nitrogen is extremely siderophilic.
10 May 2021 at 12:00am
Widespread deep seismicity in the Delaware Basin, Texas, is mainly driven by shallow wastewater injection [Earth, Atmospheric, and Planetary Sciences]
by Guang Zhai, Manoochehr Shirzaei, Michael Manga
Industrial activity away from plate boundaries can induce earthquakes and has evolved into a global issue. Much of the induced seismicity in the United States' midcontinent is attributed to a direct pressure increase from deep wastewater disposal. This mechanism is not applicable where deep basement faults are hydraulically isolated from...
10 May 2021 at 9:07pm
Isoelectronic perturbations to f-d-electron hybridization and the enhancement of hidden order in URu2Si2 [Physics]
by Christian T. Wolowiec, Noravee Kanchanavatee, Kevin Huang, Sheng Ran, Alexander J. Breindel, Naveen Pouse, Kalyan Sasmal, Ryan E. Baumbach, Greta Chappell, Peter S. Riseborough, M. Brian Maple
Electrical resistivity measurements were performed on single crystals of URu2–xOsxSi2 up to x = 0.28 under hydrostatic pressure up to P = 2 GPa. As the Os concentration, x, is increased, 1) the lattice expands, creating an effective negative chemical pressure Pch(x); 2) the hidden-order (HO) phase is enhanced and...
11 May 2021 at 8:21pm
Rules of formation of H-C-N-O compounds at high pressure and the fates of planetary ices [Earth, Atmospheric, and Planetary Sciences]
by Lewis J. Conway, Chris J. Pickard, Andreas Hermann
The solar system’s outer planets, and many of their moons, are dominated by matter from the H–C–N–O chemical space, based on solar system abundances of hydrogen and the planetary ices H2O, CH4, and NH3. In the planetary interiors, these ices will experience extreme pressure conditions, around 5 Mbar at the...
30 Apr 2021 at 8:34pm
Adsorption of simple gases into the porous glass MCM-41
by Alan K. Soper
The Journal of Chemical Physics, Volume 154, Issue 18, May 2021.
The porous glass MCM-41 is an important adsorbent to study the process of adsorption of gases onto a cylindrical surface. In this work, we study the adsorption of oxygen, nitrogen, deuterium, and deuteriated methane gases into MCM-41 using a combination of neutron diffraction analysis and atomistic computer modeling to interpret the measured data. Adsorption is achieved by immersing a sample of MCM-41 in a bath of the relevant gas, keeping the gas pressure constant (0.1 MPa), and lowering the temperature in steps toward the corresponding bulk liquid boiling point. All four gases have closely analogous behaviors, with an initial layering of liquid on the inside surface of the pores, followed by a relatively sharp capillary condensation (CC) when the pore becomes filled with dense fluid, signaled by a sharp decrease in the intensity of (100) Bragg diffraction reflection. At the temperature of CC, there is a marked distortion of the hexagonal lattice of pores, as others have seen, which relaxes close to the original structure after CC, and this appears to be accompanied by notable excess heterogeneity along the pore compared to when CC is complete. In none of the four gases studied does the final density of fluid in the pore fully attain the value of the bulk liquid at its boiling point at this pressure, although it does approach that limit closely near the center of the pore, and in all cases, the pronounced layering near the silica interface seen in previous studies is observed here as well.
10 May 2021 at 11:54am
Structural and topological changes across the liquid–liquid transition in water
by Riccardo Foffi
The Journal of Chemical Physics, Volume 154, Issue 18, May 2021.
It has recently been shown that the TIP4P/Ice model of water can be studied numerically in metastable equilibrium at and below its liquid–liquid critical temperature. We report here simulations along a subcritical isotherm, for which two liquid states with the same pressure and temperature but different density can be equilibrated. This allows for a clear visualization of the structural changes taking place across the transition. We specifically focus on how the topological properties of the H-bond network change across the liquid–liquid transition. Our results demonstrate that the structure of the high-density liquid, characterized by the existence of interstitial molecules and commonly explained in terms of the collapse of the second neighbor shell, actually originates from the folding back of long rings, bringing pairs of molecules separated by several hydrogen-bonds close by in space.
12 May 2021 at 11:57am
Crystal growth of bcc titanium from the melt and interfacial properties: A molecular dynamics simulation study
by R. E. Rozas
The Journal of Chemical Physics, Volume 154, Issue 18, May 2021.
The crystal growth kinetics and interfacial properties of titanium (Ti) are studied using molecular dynamics computer simulation. The interactions between the Ti atoms are modeled via an embedded atom method potential. First, the free solidification method (FSM) is used to determine the melting temperature Tm at zero pressure where the transition from liquid to body-centered cubic crystal occurs. From the simulations with the FSM, the kinetic growth coefficients are also determined for different orientations of the crystal, analyzing how the coupling to the thermostat affects the estimates of the growth coefficients. At Tm, anisotropic interfacial stiffnesses and free energies as well as kinetic growth coefficients are determined from capillary wave fluctuations. The so-obtained growth coefficients from equilibrium fluctuations and without the coupling of the system to a thermostat agree well with those extracted from the FSM calculations.
11 May 2021 at 11:55am
Mechanisms for Pressure-Induced Isostructural Phase Transitions in EuO
by Jacques K. Desmarais, Alessandro Erba, Yuanming Pan, Bartolomeo Civalleri, and John S. Tse
Author(s): Jacques K. Desmarais, Alessandro Erba, Yuanming Pan, Bartolomeo Civalleri, and John S. Tse

We study pressure-induced isostructural electronic phase transitions in the prototypical mixed valence and strongly correlated material EuO using the global-hybrid density functional theory. The simultaneous presence in the valence of highly localized $d$- and $f$-type bands and itinerant $s$- and $... [Phys. Rev. Lett. 126, 196404] Published Wed May 12, 2021 12 May 2021 at 12:00pm Ion Heating and Flow Driven by an Instability Found in Plasma Couette Flow by J. Milhone, K. Flanagan, J. Egedal, D. Endrizzi, J. Olson, E. E. Peterson, J. C. Wright, and C. B. Forest Author(s): J. Milhone, K. Flanagan, J. Egedal, D. Endrizzi, J. Olson, E. E. Peterson, J. C. Wright, and C. B. Forest We present the first observation of instability in weakly magnetized, pressure dominated plasma Couette flow firmly in the Hall regime. Strong Hall currents couple to a low frequency electromagnetic mode that is driven by high-$β$($>1$) pressure profiles. Spectroscopic measurements show heating ... [Phys. Rev. Lett. 126, 185002] Published Wed May 05, 2021 5 May 2021 at 12:00pm Friction on Ice: How Temperature, Pressure, and Speed Control the Slipperiness of Ice by Rinse W. Liefferink, Feng-Chun Hsia, Bart Weber, and Daniel Bonn Author(s): Rinse W. Liefferink, Feng-Chun Hsia, Bart Weber, and Daniel Bonn A new approach for studying friction on ice helps explain why the ease of sliding depends strongly on temperature, contact pressure, and speed. [Phys. Rev. X 11, 011025] Published Mon Feb 08, 2021 8 Feb 2021 at 11:00am Emergent Magnetic Phases in Pressure-Tuned van der Waals Antiferromagnet${\mathrm{FePS}}_{3}$by Matthew J. Coak, David M. Jarvis, Hayrullo Hamidov, Andrew R. Wildes, Joseph A. M. Paddison, Cheng Liu, Charles R. S. Haines, Ngoc T. Dang, Sergey E. Kichanov, Boris N. Savenko, Sungmin Lee, Marie Kratochvílová, Stefan Klotz, Thomas C. Hansen, Denis P. Kozlenko, Je-Geun Park, and Siddharth S. Saxena Author(s): Matthew J. Coak, David M. Jarvis, Hayrullo Hamidov, Andrew R. Wildes, Joseph A. M. Paddison, Cheng Liu, Charles R. S. Haines, Ngoc T. Dang, Sergey E. Kichanov, Boris N. Savenko, Sungmin Lee, Marie Kratochvílová, Stefan Klotz, Thomas C. Hansen, Denis P. Kozlenko, Je-Geun Park, and Siddharth S. Saxena High-pressure neutron studies of so-called magnetic graphene unveil exotic new states and behaviors as the material transitions from an insulator to a metal when compressed. [Phys. Rev. X 11, 011024] Published Fri Feb 05, 2021 5 Feb 2021 at 11:00am Structural motifs and bonding in two families of boron structures predicted at megabar pressures by Katerina P. Hilleke, Tadashi Ogitsu, Shuai Zhang, and Eva Zurek Author(s): Katerina P. Hilleke, Tadashi Ogitsu, Shuai Zhang, and Eva Zurek The complex crystal chemistry of elemental boron has led to numerous proposed structures with distinctive motifs as well as contradictory findings. Herein, evolutionary structure searches performed at 100 GPa have uncovered a series of metastable phases of boron, and bonding analyses were carried ou... [Phys. Rev. Materials 5, 053605] Published Fri May 14, 2021 14 May 2021 at 12:00pm Phase transition pathway of hybrid halide perovskites under compression: Insights from first-principles calculations by Dongwen Yang, Yuhao Fu, Yuanhui Sun, Yawen Li, Kai Wang, Zewen Xiao, Koushik Biswas, and Lijun Zhang Author(s): Dongwen Yang, Yuhao Fu, Yuanhui Sun, Yawen Li, Kai Wang, Zewen Xiao, Koushik Biswas, and Lijun Zhang Lead halide perovskites undergo pressure-induced phase transition, facilitated by bond compressions and different tilt patterns of the${\mathrm{PbI}}_{6}$octahedra. Utilizing first-principles calculations we investigated 14 possible tilt systems of${\mathrm{CH}}_{3}{\mathrm{NH}}_{3}{\mathrm{PbI}}...

[Phys. Rev. Materials 5, 054603] Published Mon May 10, 2021
10 May 2021 at 12:00pm
Erratum: Pressure-induced yttrium oxides with unconventional stoichiometries and novel properties [Phys. Rev. Materials 5, 044802 (2021)]
by Qiuping Yang, Jianyan Lin, Fei Li, Jing Zhang, Eva Zurek, and Guochun Yang
Author(s): Qiuping Yang, Jianyan Lin, Fei Li, Jing Zhang, Eva Zurek, and Guochun Yang
[Phys. Rev. Materials 5, 059901] Published Tue May 04, 2021
4 May 2021 at 12:00pm
Revealing defect-induced spin disorder in nanocrystalline Ni
by Mathias Bersweiler, Evelyn Pratami Sinaga, Inma Peral, Nozomu Adachi, Philipp Bender, Nina-Juliane Steinke, Elliot Paul Gilbert, Yoshikazu Todaka, Andreas Michels, and Yojiro Oba
Author(s): Mathias Bersweiler, Evelyn Pratami Sinaga, Inma Peral, Nozomu Adachi, Philipp Bender, Nina-Juliane Steinke, Elliot Paul Gilbert, Yoshikazu Todaka, Andreas Michels, and Yojiro Oba

We combine magnetometry and magnetic small-angle neutron scattering to study the influence of the microstructure on the macroscopic magnetic properties of a nanocrystalline Ni bulk sample, which was prepared by straining via high-pressure torsion (HPT). As seen by magnetometry, the mechanical deform...

[Phys. Rev. Materials 5, 044409] Published Tue Apr 20, 2021
20 Apr 2021 at 12:00pm
Pressure effect on diffusion of carbon at the $85.{91}^{∘}\phantom{\rule{0.16em}{0ex}}〈100〉$ symmetric tilt grain boundary of $α$-iron
by Md Mijanur Rahman, Fedwa El-Mellouhi, Othmane Bouhali, Charlotte S. Becquart, and Normand Mousseau
Author(s): Md Mijanur Rahman, Fedwa El-Mellouhi, Othmane Bouhali, Charlotte S. Becquart, and Normand Mousseau

The diffusion mechanism of carbon in iron plays a vital role in carburization processes, steel fabrication, and metal dusting corrosion. In this paper, using the kinetic activation-relaxation technique (k-ART), an off-lattice kinetic Monte Carlo algorithm with on-the-fly catalog building that allows...

[Phys. Rev. Materials 5, 043605] Published Mon Apr 19, 2021
19 Apr 2021 at 12:00pm
Pressure-induced yttrium oxides with unconventional stoichiometries and novel properties
by Qiuping Yang, Jianyan Lin, Fei Li, Jing Zhang, Eva Zurek, and Guochun Yang
Author(s): Qiuping Yang, Jianyan Lin, Fei Li, Jing Zhang, Eva Zurek, and Guochun Yang

The oxygenic motifs (e.g., ${\mathrm{O}}^{2–}$, ${{\mathrm{O}}_{2}}^{2\text{–}}$ ${{\mathrm{O}}_{2}}^{2\text{–}}$, and ${{\mathrm{O}}_{2}}^{\text{–}}$) that are present in compounds have a substantial effect on their electronic structure and behavior. Herein, first-principles swarm-intelligence crys...

[Phys. Rev. Materials 5, 044802] Published Fri Apr 09, 2021
9 Apr 2021 at 12:00pm
Latent heat method to detect melting and freezing of metals at megabar pressures
by Zachary M. Geballe, Nicholas Holtgrewe, Amol Karandikar, Eran Greenberg, Vitali B. Prakapenka, and Alexander F. Goncharov
Author(s): Zachary M. Geballe, Nicholas Holtgrewe, Amol Karandikar, Eran Greenberg, Vitali B. Prakapenka, and Alexander F. Goncharov

The high-pressure melting curves of metals provide simple and useful tests for theories of melting, as well as important constraints for the modeling of planetary interiors. Here, we present an experimental technique that reveals the latent heat of fusion of a metal sample compressed inside a diamon...

[Phys. Rev. Materials 5, 033803] Published Fri Mar 26, 2021
26 Mar 2021 at 11:00am
Exploration of Hg-based cuprate superconductors by Raman spectroscopy under hydrostatic pressure
by N. Auvray, B. Loret, S. Chibani, R. Grasset, Y. Guarnelli, P. Parisiades, A. Forget, D. Colson, M. Cazayous, Y. Gallais, and A. Sacuto
Author(s): N. Auvray, B. Loret, S. Chibani, R. Grasset, Y. Guarnelli, P. Parisiades, A. Forget, D. Colson, M. Cazayous, Y. Gallais, and A. Sacuto

The superconducting phase of the ${\mathrm{HgBa}}_{2}{\mathrm{CuO}}_{4+δ}$ (Hg-1201) and ${\mathrm{HgBa}}_{2}{\mathrm{Ca}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{8+δ}$ (Hg-1223) cuprates has been investigated by Raman spectroscopy under hydrostatic pressure. Our analysis reveals that the increase of ${T}... [Phys. Rev. B 103, 195130] Published Thu May 13, 2021 13 May 2021 at 12:00pm Synchrotron Mössbauer spectroscopic and x-ray diffraction study of ferropericlase in the high-pressure range of the lower mantle region by Maki Hamada, Seiji Kamada, Eiji Ohtani, Tatsuya Sakamaki, Takaya Mitsui, Ryo Masuda, Naohisa Hirao, Yasuo Ohishi, and Masahide Akasaka Author(s): Maki Hamada, Seiji Kamada, Eiji Ohtani, Tatsuya Sakamaki, Takaya Mitsui, Ryo Masuda, Naohisa Hirao, Yasuo Ohishi, and Masahide Akasaka Systematic change of structural transition and high-spin (HS) to low-spin (LS) transition of${\mathrm{Fe}}^{2+}$in synthetic$({\mathrm{Mg}}_{0.6}{\mathrm{Fe}}_{0.4})\mathrm{O}$-ferropericlase for pressures up to that of the lower mantle region were investigated using synchrotron x-ray diffraction... [Phys. Rev. B 103, 174108] Published Wed May 12, 2021 12 May 2021 at 12:00pm In situ synchrotron diffraction of pressure-induced phase transition in${\mathrm{DyPO}}_{4}$under variable hydrostaticity by Jai Sharma, Matthew Musselman, Bianca Haberl, and Corinne E. Packard Author(s): Jai Sharma, Matthew Musselman, Bianca Haberl, and Corinne E. Packard In situ synchrotron x-ray diffraction was conducted on polycrystalline${\mathrm{DyPO}}_{4}$to elucidate the details of the pressure-induced transition from the xenotime polymorph to the monazite polymorph. We used three different pressure-transmitting media (neon, a 16:3:1 methanol-ethanol-water m... [Phys. Rev. B 103, 184105] Published Wed May 12, 2021 12 May 2021 at 12:00pm Pressure-dependent modifications in the$\mathrm{LaAu}{\mathrm{Sb}}_{2}$charge density wave system by Govindaraj Lingannan, Boby Joseph, Ponniah Vajeeston, Chia Nung Kuo, Chin Shan Lue, Ganesan Kalaiselvan, Piu Rajak, and Sonachalam Arumugam Author(s): Govindaraj Lingannan, Boby Joseph, Ponniah Vajeeston, Chia Nung Kuo, Chin Shan Lue, Ganesan Kalaiselvan, Piu Rajak, and Sonachalam Arumugam Hydrostatic pressure response of$\mathrm{LaAu}{\mathrm{Sb}}_{2}$charge density wave (CDW) system is investigated using electrical transport, x-ray diffraction (XRD), and density-functional theory (DFT). Resistivity data at ambient pressure evidence a clear CDW transition at 83 K. X-ray diffraction... [Phys. Rev. B 103, 195126] Published Wed May 12, 2021 12 May 2021 at 12:00pm Ab initio molecular dynamics investigation of the elastic properties of superionic${\mathrm{Li}}_{2}\mathrm{O}$under high temperature and pressure by Yu He, Shichuan Sun, and Heping Li Author(s): Yu He, Shichuan Sun, and Heping Li Theoretical prediction on the elastic properties of superionic material is challenging due to the fast diffusion of cation/anion in the lattice. Here, we investigated the elastic properties of${\mathrm{Li}}_{2}\mathrm{O}\$ at elevated temperature and pressure using ab initio molecular dynamics (AIMD...

[Phys. Rev. B 103, 174105] Published Mon May 10, 2021
10 May 2021 at 12:00pm
In situ electrical resistivity and viscosity measurements of iron alloys under pressure using synchrotron X-ray radiography
by A. Pommier
Volume 41, Issue 1, March 2021, Page 1-13
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29 Dec 2020 at 3:18am
The solubility behavior of NaCl in water at high pressure studied by neutron diffraction and Raman scattering
by Qiwei Hu
Volume 41, Issue 1, March 2021, Page 39-51
.

4 Jan 2021 at 10:17am
Structure and vibration spectra of strontium and magnesium oxalates at high pressure
by I.G. Batyrev
Volume 41, Issue 1, March 2021, Page 52-64
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9 Mar 2021 at 2:11am
High-pressure and high-temperature neutron-diffraction experiments using Kawai-type multi-anvil assemblies
by Asami Sano-Furukawa
Volume 41, Issue 1, March 2021, Page 65-74
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11 Jan 2021 at 5:30am
Pressure calibration based on the ultrasonic measurement in multi-anvil apparatus
by Wei Song
Volume 41, Issue 1, March 2021, Page 75-87
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26 Dec 2020 at 10:38am
Clamp cells for high pressure neutron scattering at low temperatures and high magnetic fields at Heinz Maier-Leibnitz Zentrum (MLZ)
by A. Eich
Volume 41, Issue 1, March 2021, Page 88-96
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12 Nov 2020 at 7:18am
Preparation of SEM hydrogel samples using a high pressure water freeze fracture method
by Hirofumi Satani
Volume 41, Issue 1, March 2021, Page 97-108
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26 Dec 2020 at 10:35am
Pressure tolerance of brine shrimp (Artemia)
by Ryo Kitahara
Volume 41, Issue 1, March 2021, Page 109-117
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15 Dec 2020 at 3:54am
Hydrostaticity in high pressure experiments: some general observations and guidelines for high pressure experimenters
by K. Takemura
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25 Mar 2021 at 6:06am
Using high hydrostatic pressure as an abiotic elicitor strategy for improving capsaicin production in free and immobilized cell suspension cultures of Capsicum annuum L.
by Cemil İşlek
.

25 Mar 2021 at 6:03am
Product design gets an AI makeover
by MIT Technology Review Insights
Engineers are under unprecedented pressure to build products that are used by thousands, if not millions, of consumers every day. Just ask Bernd Zapf. Head of development, new business, and technologies at Heller Group, a machine tool manufacturer in Germany, Zapf says today’s organizations must increasingly “strike a balance between the design, engineering, manufacturing, operation,…
10 May 2021 at 4:00pm