The Review of High Pressure Science and Technology
Online ISSN : 1348-1940
Print ISSN : 0917-639X
ISSN-L : 0917-639X
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Volume 23, Issue 2
Displaying 1-14 of 14 articles from this issue
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Foreword
Reviews—Progress of High-Pressure Materials Science with Computer—
  • High-Pressure Materials Science with K Computer
    Shinji TSUNEYUKI
    2013 Volume 23 Issue 2 Pages 88-93
    Published: 2013
    Released on J-STAGE: June 26, 2013
    DOIhttps://doi.org/10.4131/jshpreview.23.88
    JOURNAL FREE ACCESS
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      In this article, recent advances in computational materials science accelerated by K computer and high-performance computing infrastructures are reviewed. Exponentially growing computer power enables us to develop and apply new methodologies of computer ssimulation, which will realize qualitatively different approach to high-pressure science.
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  • Thermodynamic Stability of Clathrate Hydrates
    Hideki TANAKA, Masakazu MATSUMOTO
    2013 Volume 23 Issue 2 Pages 94-102
    Published: 2013
    Released on J-STAGE: June 26, 2013
    DOIhttps://doi.org/10.4131/jshpreview.23.94
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      We review recent advances in prediction of phase behaviors of various clathrate hydrates with firm statistical mechanical ground, in which the classical theory is extended to multiple occupation of cages and substitution of a fully occupied state for an empty hydrate structure. It is demonstrated that they indeed work effectively in predicting the dissociation pressures of clathrate hydrates containing hydrogen and some hydrocarbon molecules.
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  • Ab Initio Computation Study for Earth and Planetary Physics
    Taku TSUCHIYA
    2013 Volume 23 Issue 2 Pages 103-112
    Published: 2013
    Released on J-STAGE: June 26, 2013
    DOIhttps://doi.org/10.4131/jshpreview.23.103
    JOURNAL FREE ACCESS
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      Recent progress in theoretical mineral physics based on the ab initio quantum mechanical computation method has been dramatic in conjunction with the advancement of computer technologies. It is now possible to predict stability and several physical properties of complex minerals quantitatively not only at high pressures but also at high temperatures with uncertainties that are comparable to or even smaller than those attached in experimental data. Our present challenges include calculations of high-P,T elasticity to constrain the lower mantle mineralogy, transport properties such as lattice thermal conductivity, and further extensions to terapascal phase equilibria of Earth materials for studying planetary interiors.
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  • Research on Crystal Structure and Superconductivity of Materials by Computer Simulations: Crystal Structure Prediction Using Metadynamics and Genetic Algorithm
    Takahiro ISHIKAWA
    2013 Volume 23 Issue 2 Pages 113-123
    Published: 2013
    Released on J-STAGE: June 26, 2013
    DOIhttps://doi.org/10.4131/jshpreview.23.113
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      Crystal structure determination is one of grand challenges in high-pressure materials science, and the structure prediction by computer simulations based on ab-initio calculations has played a significantly important role for it. In this article, metadynamics and genetic algorithm are focused on as the computational technique of the crystal structure searching. First, phosphorus and calcium are brought up as successful examples of the ab-initio metadynamics simulation. Then, the high-pressure phases of yttrium are shown as the results obtained by the application of the ab-initio genetic algorithm. In addition, for the three elements, the superconducting properties theoretically obtained by the use of the predicted crystal structures are compared with experimental ones.
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  • Simulating Proton Dynamics in High-Pressure Ice
    Toshiaki IITAKA
    2013 Volume 23 Issue 2 Pages 124-132
    Published: 2013
    Released on J-STAGE: June 26, 2013
    DOIhttps://doi.org/10.4131/jshpreview.23.124
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      Proton dynamics in hydrogen-bonded systems, in particular, dissociation and recombination of water molecules are basic processes in many chemical and life systems. In this article, we discuss the pressure dependence of electric conductivity of high-pressure ices VII and X, which may exist in astronomical icy bodies, from the following three viewpoints: (1) molecular dynamics simulation of the hydrogen and oxygen atoms, (2) thermodynamic transport theory of ionic and rotational defects of ice, (3) lattice model of proton hopping.
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  • Powder X-Ray Structure Analysis with Density Functional Theory Calculations
    Hiroshi FUJIHISA, Nozomu HAMAYA, Hiroshi YAMAWAKI, Satoshi TAKEYA, Yos ...
    2013 Volume 23 Issue 2 Pages 133-140
    Published: 2013
    Released on J-STAGE: June 26, 2013
    DOIhttps://doi.org/10.4131/jshpreview.23.133
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      Information of a crystal structure is crucial for understanding its physical properties. Our previous powder x-ray structure analyses on proton conductors, high-energy materials, and elements under conditions of high-temperatures, low-temperatures, high-pressures have revealed their new crystal structures, however, precise positions of light elements like hydrogen or lithium remained unknown. Therefore, we employed a density functional theory (DFT) calculation and found that it could collaborate successfully with the powder x-ray experiments. In this article, we report some techniques used in our recent structure analyses.
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Reviews
Review: 2012 JSHPST Award
Review: 2012 JSHPST Award for Young Scientists
  • Imaging of Phosphatidylcholine Bilayers by a High-Pressure Fluorometry
    Masaki GOTO
    2013 Volume 23 Issue 2 Pages 157-166
    Published: 2013
    Released on J-STAGE: June 26, 2013
    DOIhttps://doi.org/10.4131/jshpreview.23.157
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      High-pressure fluorescence study using a polarity-sensitive probe Prodan on phosphatidylcholine (PC) bilayers is reviewed. The author has constructed a three-dimensional image plot based on the second-derivative of the Prodan fluorescence spectra that change depending on the phase state of the PC bilayers, which enables us to examine the packing state of the bilayer. The effects of (1) acyl chain length, (2) vesicle size, and (3) chain asymmetry on the PC bilayers are discussed by using the technique of bilayer imaging. Further the formation of the lamellar crystal phase of the PC bilayer is also revealed by the technique.
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  • High-Pressure Synthesis of Novel Transition Metal Oxides Containing Unusual High Valence Ions
    Ikuya YAMADA
    2013 Volume 23 Issue 2 Pages 167-173
    Published: 2013
    Released on J-STAGE: June 26, 2013
    DOIhttps://doi.org/10.4131/jshpreview.23.167
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      High-pressure synthesis method can generate novel materials containing unusual high valence ions. CaCu3Fe4O12 and SrCu3Fe4O12 perovskites, with unusual high valence Fe4+ ions, demonstrate anomalous properties such as charge disproportionation, and intersite charge transfer. CaCu3Fe4O12 shows a charge disproportionation of 2Fe4+→Fe3++Fe5+ type whereas SrCu3Fe4O12 shows a crossover-like intersite charge transfer between Cu and Fe between 170 and 270 K. This gradual transition results in a giant negative thermal expansion with a linear thermal expansion coefficient of −2.26×10−5 K−1, followed by the charge disproportionation at a ratio of Fe3+:Fe5+≒4:1. The differences in the structural and electronic properties between CaCu3Fe4O12 and SrCu3Fe4O12 are attributed to the bond strains induced by A-site cations.
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