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 EHPRG Meeting

 

The 57th European High Pressure Research Group Meeting on High Pressure Science and Technology (EHPRG-2019) will be held in Prague, Czech Republic, from 1st to 6th September 2019. The 57th EHPRG Meeting will be chaired by Jiří Prchal (Charles University, Prague, Czech Republic).
For more information, please visit the official webpage of the 57th EHPRG Meeting.

High-pressure in the headlines

 

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

    Snailfish is first animal from extreme ocean depths to get genome sequenced
    by Erin I. Garcia de Jesus

    Snailfish is first animal from extreme ocean depths to get genome sequenced

    Snailfish is first animal from extreme ocean depths to get genome sequenced, Published online: 15 April 2019; doi:10.1038/d41586-019-01158-x

    Gene sequence from fish living in the Mariana Trench reveals clues to living life under pressure.
    15 Apr 2019 at 12:00am
    Theoretical equations of state for a charged fluid
    by X. Sánchez-Monroy
    The Journal of Chemical Physics, Volume 150, Issue 14, April 2019.
    In this article, we present a molecular thermodynamic study of a system of N particles contained within a volume V and interacting via a hard-core pair potential with an attractive interaction according to the Wolf model for charged systems. This variable-range potential is characterized by three parameters: the repulsive hard-core diameter σ, the energy-well depth ϵ, and the inverse range α; a fourth parameter of the model is a cut-off distance xc that depends on α according to the relation xc = 2/α. Two equations of state (EOSs) are presented and derived from thermodynamic perturbation theory and Monte Carlo (MC) simulation data. The first EOS is given by the standard Zwanzig’s high-temperature expansion of the Helmholtz free energy, where the first three perturbation terms a1, a2, and a3 were obtained from MC simulations in the canonical ensemble (NVT) and parameterized as functions of α and the reduced density of particles ρ* = Nσ3/V. The second EOS was obtained from the discrete perturbation theory applied to a discrete representation of the Wolf potential. Results for pressures, internal energies, and isochoric heat capacities are compared to the MC computer simulation data of the Wolf system, including vapor-liquid coexistence curves, for different values of α. Overall, both EOSs give a very good representation of the thermodynamic properties of the Wolf fluid when 0.3 ≤ α ≤ 1.0 and 0.05 ≤ ρ* ≤ 0.8. Since the Yukawa fluid can reproduce information of screened ionic interactions, we discuss the equivalence between the Wolf and Yukawa fluids in the context of equivalent systems in liquid theory.
    10 Apr 2019 at 10:13am
    Molecular dynamics simulations of nano-confined methanol and methanol-water mixtures between infinite graphite plates: Structure and dynamics
    by Hamid Mosaddeghi
    The Journal of Chemical Physics, Volume 150, Issue 14, April 2019.
    Molecular dynamics simulations are used to investigate microscopic structures and dynamics of methanol and methanol-water binary mixture films confined between hydrophobic infinite parallel graphite plate slits with widths, H, in the range of 7–20 Å at 300 K. The initial geometric densities of the liquids were chosen to be the same as bulk methanol at the same temperature. For the two narrowest slit widths, two smaller initial densities were also considered. For the nano-confined system with H = 7 Å and high pressure, a solid-like hexagonal arrangement of methanol molecules arranged perpendicular to the plates is observed which reflects the closest packing of the molecules and partially mirrors the structure of the underlying graphite structure. At lower pressures and for larger slit widths, in the contact layer, the methanol molecules prefer having the C–O bond oriented parallel to the walls. Layered structures of methanol parallel to the wall were observed, with contact layers and additional numbers of central layers depending on the particular slit width. For methanol–water mixtures, simulations of solutions with different composition were performed between infinite graphite slits with H = 10 and 20 Å at 300 K. For the nanoslit with H = 10 Å, in the solution mixtures, three layers of molecules form, but for all mole fractions of methanol, methanol molecules are excluded from the central fluid layer. In the nanopore with H = 20 Å, more than three fluid layers are formed and methanol concentrations are enhanced near the confining plates walls compared to the average solution stoichiometry. The self-diffusion coefficients of methanol and water molecules in the solution show strong dependence on the solution concentration. The solution mole fractions with minimal diffusivity are the same in confined and non-confined bulk methanol-water mixtures.
    11 Apr 2019 at 10:42am
    Thermal Conductivity Enhancement in ${\mathrm{MoS}}_{2}$ under Extreme Strain
    by Xianghai Meng, Tribhuwan Pandey, Jihoon Jeong, Suyu Fu, Jing Yang, Ke Chen, Akash Singh, Feng He, Xiaochuan Xu, Jianshi Zhou, Wen-Pin Hsieh, Abhishek K. Singh, Jung-Fu Lin, and Yaguo Wang
    Author(s): Xianghai Meng, Tribhuwan Pandey, Jihoon Jeong, Suyu Fu, Jing Yang, Ke Chen, Akash Singh, Feng He, Xiaochuan Xu, Jianshi Zhou, Wen-Pin Hsieh, Abhishek K. Singh, Jung-Fu Lin, and Yaguo Wang

    Because of their weak interlayer bonding, van der Waals (vdW) solids are very sensitive to external stimuli such as strain. Experimental studies of strain tuning of thermal properties in vdW solids have not yet been reported. Under $∼9%$ cross-plane compressive strain created by hydrostatic pressure...


    [Phys. Rev. Lett. 122, 155901] Published Thu Apr 18, 2019
    18 Apr 2019 at 12:00pm
    Pressure-Induced Phase Transitions in Germanium Telluride: Raman Signatures of Anharmonicity and Oxidation
    by Amit Pawbake, Christophe Bellin, Lorenzo Paulatto, Keevin Béneut, Johan Biscaras, Chandrabhas Narayana, Dattatray J. Late, and Abhay Shukla
    Author(s): Amit Pawbake, Christophe Bellin, Lorenzo Paulatto, Keevin Béneut, Johan Biscaras, Chandrabhas Narayana, Dattatray J. Late, and Abhay Shukla

    Pressure-induced phase transitions in GeTe, a prototype phase change material, have been studied to date with diffraction which is not sensitive to anharmonicity-induced dynamical effects. GeTe is also prone to surface oxidation which may compromise surface sensitive measurements. These factors coul...


    [Phys. Rev. Lett. 122, 145701] Published Tue Apr 09, 2019
    9 Apr 2019 at 12:00pm
    Persistent Octahedral Coordination in Amorphous ${\mathrm{GeO}}_{2}$ Up to 100 GPa by $\mathrm{K}{β}^{′′}$ X-Ray Emission Spectroscopy
    by G. Spiekermann, M. Harder, K. Gilmore, P. Zalden, Ch. J. Sahle, S. Petitgirard, M. Wilke, N. Biedermann, C. Weis, W. Morgenroth, J. S. Tse, E. Kulik, N. Nishiyama, H. Yavaş, and C. Sternemann
    Author(s): G. Spiekermann, M. Harder, K. Gilmore, P. Zalden, Ch. J. Sahle, S. Petitgirard, M. Wilke, N. Biedermann, C. Weis, W. Morgenroth, J. S. Tse, E. Kulik, N. Nishiyama, H. Yavaş, and C. Sternemann

    X-ray emission spectra reveal that under pressure conditions of Earth’s lower mantle, the compaction mechanism in amorphous germanium dioxide on the atomic scale is similar to that of its crystalline form.


    [Phys. Rev. X 9, 011025] Published Wed Feb 06, 2019
    6 Feb 2019 at 11:00am
    Multisite Exchange-Enhanced Barocaloric Response in ${\mathrm{Mn}}_{3}\mathrm{NiN}$
    by David Boldrin, Eduardo Mendive-Tapia, Jan Zemen, Julie B. Staunton, Thomas Hansen, Araceli Aznar, Josep-Lluís Tamarit, Maria Barrio, Pol Lloveras, Jiyeob Kim, Xavier Moya, and Lesley F. Cohen
    Author(s): David Boldrin, Eduardo Mendive-Tapia, Jan Zemen, Julie B. Staunton, Thomas Hansen, Araceli Aznar, Josep-Lluís Tamarit, Maria Barrio, Pol Lloveras, Jiyeob Kim, Xavier Moya, and Lesley F. Cohen

    Experiments reveal that Mn3NiN has enormous ability to control heat flow when subjected to mechanical pressure, establishing the family of Mn-antiperovskite materials as promising tools for energy-efficient refrigeration.


    [Phys. Rev. X 8, 041035] Published Wed Nov 28, 2018
    28 Nov 2018 at 11:00am
    Solids, liquids, and gases under high pressure
    by Ho-Kwang Mao, Xiao-Jia Chen, Yang Ding, Bing Li, and Lin Wang
    Author(s): Ho-Kwang Mao, Xiao-Jia Chen, Yang Ding, Bing Li, and Lin Wang

    The effect of adding high pressure as a control parameter in solids, liquids, and gases expands opportunities to observe unexpected novel phenomena and understand matter in extreme environments. This review on high pressure science highlights subjects ranging from quantum criticality to Earth science. State-of-the-art experimental methods at megabar pressures are also discussed. The proliferation of pressure-induced phases illustrate promising new directions for this field of research.


    [Rev. Mod. Phys. 90, 015007] Published Tue Mar 20, 2018
    20 Mar 2018 at 11:00am
    Colloquium: High pressure and road to room temperature superconductivity
    by Lev P. Gor’kov and Vladimir Z. Kresin
    Author(s): Lev P. Gor’kov and Vladimir Z. Kresin

    Even after three decades of development, high-temperature superconductivity remains one of the most challenging theoretical and experimental areas in condensed matter physics. In this Colloquium some new discoveries in this area are reviewed and possible routes toward much higher transition temperatures are analyzed.


    [Rev. Mod. Phys. 90, 011001] Published Tue Jan 09, 2018
    9 Jan 2018 at 11:00am
    Equations of state for supernovae and compact stars
    by M. Oertel, M. Hempel, T. Klähn, and S. Typel
    Author(s): M. Oertel, M. Hempel, T. Klähn, and S. Typel

    What are the thermodynamic properties of matter at extreme densities, even exceeding nuclear matter density severely? How can we describe the composition of matter for such conditions, the resulting pressure, and the maximum mass of cold neutron stars? How is this affected by finite temperatures, as they occur in core collapse supernovae and in compact star mergers? This review addresses these points within the framework of constraints from experiments as well as astronomical observations.


    [Rev. Mod. Phys. 89, 015007] Published Wed Mar 15, 2017
    15 Mar 2017 at 11:00am
    Ambipolar suppression of superconductivity by ionic gating in optimally doped ${\mathrm{BaFe}}_{2}{(\mathrm{As},\mathrm{P})}_{2}$ ultrathin films
    by Erik Piatti, Takafumi Hatano, Dario Daghero, Francesco Galanti, Claudio Gerbaldi, Salvatore Guastella, Chiara Portesi, Ibuki Nakamura, Ryosuke Fujimoto, Kazumasa Iida, Hiroshi Ikuta, and Renato S. Gonnelli
    Author(s): Erik Piatti, Takafumi Hatano, Dario Daghero, Francesco Galanti, Claudio Gerbaldi, Salvatore Guastella, Chiara Portesi, Ibuki Nakamura, Ryosuke Fujimoto, Kazumasa Iida, Hiroshi Ikuta, and Renato S. Gonnelli

    Superconductivity (SC) in the Ba-122 family of iron-based compounds can be controlled by aliovalent or isovalent substitutions, applied external pressure, and strain, the combined effects of which are sometimes studied within the same sample. Most often, the result is limited to a shift of the SC do...


    [Phys. Rev. Materials 3, 044801] Published Mon Apr 15, 2019
    15 Apr 2019 at 12:00pm
    Pressure tuning of the electrical transport properties in the Weyl semimetal TaP
    by M. Besser, R. D. dos Reis, F.-R. Fan, M. O. Ajeesh, Y. Sun, M. Schmidt, C. Felser, and M. Nicklas
    Author(s): M. Besser, R. D. dos Reis, F.-R. Fan, M. O. Ajeesh, Y. Sun, M. Schmidt, C. Felser, and M. Nicklas

    We investigated the pressure evolution of the electrical transport in the almost compensated Weyl semimetal TaP. In addition, we obtained information on the modifications of the Fermi-surface topology with pressure from the analysis of pronounced Shubnikov–de Haas (SdH) quantum oscillations present ...


    [Phys. Rev. Materials 3, 044201] Published Wed Apr 10, 2019
    10 Apr 2019 at 12:00pm
    Probing the quantum phase transition in Mott insulator ${\mathrm{BaCoS}}_{2}$ tuned by pressure and Ni substitution
    by Z. Guguchia, B. A. Frandsen, D. Santos-Cottin, S. C. Cheung, Z. Gong, Q. Sheng, K. Yamakawa, A. M. Hallas, M. N. Wilson, Y. Cai, J. Beare, R. Khasanov, R. De Renzi, G. M. Luke, S. Shamoto, A. Gauzzi, Y. Klein, and Y. J. Uemura
    Author(s): Z. Guguchia, B. A. Frandsen, D. Santos-Cottin, S. C. Cheung, Z. Gong, Q. Sheng, K. Yamakawa, A. M. Hallas, M. N. Wilson, Y. Cai, J. Beare, R. Khasanov, R. De Renzi, G. M. Luke, S. Shamoto, A. Gauzzi, Y. Klein, and Y. J. Uemura

    We present a muon spin relaxation study of the Mott transition in ${\mathrm{BaCoS}}_{2}$ using two independent control parameters: (i) pressure $p$ to tune the electronic bandwidth and (ii) Ni substitution $x$ on the Co site to tune the band filling. For both tuning parameters, the antiferromagnetic...


    [Phys. Rev. Materials 3, 045001] Published Fri Apr 05, 2019
    5 Apr 2019 at 12:00pm
    Structural transition in cold-compressed glassy carbon
    by Zhidan Zeng, Hongwei Sheng, Liuxiang Yang, Hongbo Lou, Lijie Tan, Vitali B. Prakapenka, Eran Greenberg, and Qiaoshi Zeng
    Author(s): Zhidan Zeng, Hongwei Sheng, Liuxiang Yang, Hongbo Lou, Lijie Tan, Vitali B. Prakapenka, Eran Greenberg, and Qiaoshi Zeng

    Glassy carbon (GC) distinguishes itself from other carbon materials by its unique atomic structure and properties. Cold-compressed GC gives rise to new physical properties; however, the atomistic mechanism for the transitions remains elusive. In this study, by combining in situ high-pressure x-ray d...


    [Phys. Rev. Materials 3, 033608] Published Wed Mar 27, 2019
    27 Mar 2019 at 11:00am
    Angular dependence of the upper critical field in the high-pressure $1{T}^{′}$ phase of ${\mathrm{MoTe}}_{2}$
    by Y. J. Hu, Yuk Tai Chan, Kwing To Lai, Kin On Ho, Xiaoyu Guo, Hai-Peng Sun, K. Y. Yip, Dickon H. L. Ng, Hai-Zhou Lu, and Swee K. Goh
    Author(s): Y. J. Hu, Yuk Tai Chan, Kwing To Lai, Kin On Ho, Xiaoyu Guo, Hai-Peng Sun, K. Y. Yip, Dickon H. L. Ng, Hai-Zhou Lu, and Swee K. Goh

    Superconductivity in the type-II Weyl semimetal candidate ${\mathrm{MoTe}}_{2}$ has attracted much attention due to the possible realization of topological superconductivity. Under applied pressure, the superconducting transition temperature is significantly enhanced, while the structural transition...


    [Phys. Rev. Materials 3, 034201] Published Mon Mar 25, 2019
    25 Mar 2019 at 11:00am
    Controlling the interfacial conductance in ${\mathrm{LaAlO}}_{3}/{\mathrm{SrTiO}}_{3}$ in ${90}^{∘}$ off-axis sputter deposition
    by Chunhai Yin, Dileep Krishnan, Nicolas Gauquelin, Jo Verbeeck, and Jan Aarts
    Author(s): Chunhai Yin, Dileep Krishnan, Nicolas Gauquelin, Jo Verbeeck, and Jan Aarts

    We report on the fabrication of conducting interfaces between ${\mathrm{LaAlO}}_{3}$ and ${\mathrm{SrTiO}}_{3}$ by ${90}^{∘}$ off-axis sputtering in an Ar atmosphere. At a growth pressure of 0.04 mbar the interface is metallic, with a carrier density of the order of $1×{10}^{13}\phantom{\rule{4pt}{0...


    [Phys. Rev. Materials 3, 034002] Published Tue Mar 12, 2019
    12 Mar 2019 at 11:00am
    Giant power output in lead-free ferroelectrics by shock-induced phase transition
    by Zhipeng Gao, Wei Peng, Bin Chen, Simon A. T. Redfern, Ke Wang, Baojin Chu, Qiang He, Yi Sun, Xuefeng Chen, Hengchang Nie, Wen Deng, Lingkong Zhang, Hongliang He, Genshui Wang, and Xianlin Dong
    Author(s): Zhipeng Gao, Wei Peng, Bin Chen, Simon A. T. Redfern, Ke Wang, Baojin Chu, Qiang He, Yi Sun, Xuefeng Chen, Hengchang Nie, Wen Deng, Lingkong Zhang, Hongliang He, Genshui Wang, and Xianlin Dong

    The force-electric effect in ferroelectrics is characterized by the release of bound charge during pressure/shock-induced depolarization. In contrast to other electrical energy storage systems, the charge-storage/release by the force-electric effect of ferroelectrics is determined by polarization sw...


    [Phys. Rev. Materials 3, 035401] Published Mon Mar 11, 2019
    11 Mar 2019 at 11:00am
    Superconductor-insulator transition driven by pressure-tuned intergrain coupling in nanodiamond films
    by Gufei Zhang, Yonghui Zhou, Svetlana Korneychuk, Tomas Samuely, Liwang Liu, Paul W. May, Zheng Xu, Oleksandr Onufriienko, Xuefeng Zhang, Johan Verbeeck, Peter Samuely, Victor V. Moshchalkov, Zhaorong Yang, and Horst-Günter Rubahn
    Author(s): Gufei Zhang, Yonghui Zhou, Svetlana Korneychuk, Tomas Samuely, Liwang Liu, Paul W. May, Zheng Xu, Oleksandr Onufriienko, Xuefeng Zhang, Johan Verbeeck, Peter Samuely, Victor V. Moshchalkov, Zhaorong Yang, and Horst-Günter Rubahn

    We report on the pressure-driven superconductor-insulator transition in heavily boron-doped nanodiamond films. By systematically increasing the pressure, we suppress the Josephson coupling between the superconducting nanodiamond grains. The diminished intergrain coupling gives rise to an overall ins...


    [Phys. Rev. Materials 3, 034801] Published Tue Mar 05, 2019
    5 Mar 2019 at 11:00am
    Melting curve and chemical stability of ammonia at high pressure: Combined x-ray diffraction and Raman study
    by Jean-Antoine Queyroux, Sandra Ninet, Gunnar Weck, Gaston Garbarino, Thomas Plisson, Mohamed Mezouar, and Frédéric Datchi
    Author(s): Jean-Antoine Queyroux, Sandra Ninet, Gunnar Weck, Gaston Garbarino, Thomas Plisson, Mohamed Mezouar, and Frédéric Datchi

    The melting curve and stability of ammonia (${\mathrm{NH}}_{3}$) is investigated up to 40 GPa and 3500 K by x-ray diffraction and Raman spectroscopy in the laser-heated diamond anvil cell. The ${\mathrm{NH}}_{3}$ samples were directly heated by the $10.6\phantom{\rule{0.16em}{0ex}}μ\mathrm{m}$ radia...


    [Phys. Rev. B 99, 134107] Published Fri Apr 19, 2019
    19 Apr 2019 at 12:00pm
    Study of shock waves and solitons in bulk superfluid $^{4}\mathrm{He}$
    by Xavier Buelna, Daniel Gonzalez, Adam Freund, and Jussi Eloranta
    Author(s): Xavier Buelna, Daniel Gonzalez, Adam Freund, and Jussi Eloranta

    Properties of shock waves and solitons in superfluid $^{4}\mathrm{He}$ were studied by time-resolved shadowgraph experiments and theoretical density functional theory calculations. Pressure estimates for shock waves and the bright soliton limit (0.2 MPa) were provided and compared with the semiclass...


    [Phys. Rev. B 99, 144518] Published Fri Apr 19, 2019
    19 Apr 2019 at 12:00pm
    Origin of the piezochromism in ${\mathrm{Cs}}_{2}{\mathrm{CuCl}}_{4}$: Electron-phonon and crystal-structure correlations
    by E. Jara, J. A. Barreda-Argüeso, J. González, F. Rodríguez, and R. Valiente
    Author(s): E. Jara, J. A. Barreda-Argüeso, J. González, F. Rodríguez, and R. Valiente

    By using optical absorption and Raman spectroscopy, we have investigated the effects of pressure in the structural, electronic, and vibrational properties of ${\mathrm{Cs}}_{2}{\mathrm{CuCl}}_{4}$ in the 0–20 GPa range. Our study has provided a complete characterization of the electronic and vibrati...


    [Phys. Rev. B 99, 134106] Published Thu Apr 18, 2019
    18 Apr 2019 at 12:00pm
    Structural, electronic, and dynamical properties of the tetragonal and collapsed tetragonal phases of ${\mathrm{KFe}}_{2}{\mathrm{As}}_{2}$
    by Andrzej Ptok, Małgorzata Sternik, Konrad Jerzy Kapcia, and Przemysław Piekarz
    Author(s): Andrzej Ptok, Małgorzata Sternik, Konrad Jerzy Kapcia, and Przemysław Piekarz

    Compounds with a tetragonal ${\mathrm{ThCr}}_{2}{\mathrm{Si}}_{2}$-type structure are characterized by the possibility of the isostructural phase transition from the tetragonal phase to the collapsed tetragonal phase induced by the external pressure. An example of a compound with such a phase transi...


    [Phys. Rev. B 99, 134103] Published Mon Apr 15, 2019
    15 Apr 2019 at 12:00pm