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[en] Highlights: • BiFe1−xNixO3 (x = 0–0.2) films deposited by chemical deposition technique. • Grains size: 55–60 nm (pristine BFO) and 95–100 nm (BiFe1−0.2Ni0.2O3). • Elastic modulus of the films: 51 GPa (pristine BFO) to 80 GPa (BiFe1−0.2Ni0.2O3). • Hardness of the films: 7.5 GPa (pristine BFO) to 14.5 GPa (BiFe1−0.2Ni0.2O3). • Hardness of the films is found to be following inverse Hall–Petch relation.
[en] Complete text of publication follows. New experimental results on thermodynamics and electrical conductivity of shock and isoentropically compressed hydrogen and deuterium are presented. Strongly coupled plasmas at pressures achieved 18 Mbar, Coulomb coupling parameter exceeded 450, electron degeneracy parameter came up to 290 were obtained with semi-spherical explosive-driven generators. Theoretical models for description of thermodynamics of strongly coupled hydrogen are discussed, comparison of the experimental and theoretical data for strongly non-ideal hydrogen plasmas under high energy density are presented. Experimental and theoretical problems in studying of warm dense hydrogen are discussed. Problems of accurate description of weakly coupled solar plasma on basis of astrophysical observations are discussed as well.
[en] We briefly introduce a new high-pressure transport measurement system integrated with low temperature and magnetic field that is being established as one of the user experimental stations of the Synergetic Extreme Condition User Facilities in the Huairou District of Beijing, China. To demonstrate the capabilities of the system for condensed matter research, the emergence of some pressure-induced phenomena and physics related to superconductivity found previously is also introduced, and then a perspective for such an advanced high-pressure system is presented. (topical review — synergetic extreme condition user facility: breakthroughs and opportunities for the research of physical science)
[en] We will build a cubic anvil cell (CAC) apparatus for high-pressure and low-temperature physical property measurements in the synergic extreme condition user facility (SECUF). In this article, we first introduce the operating principle, the development history, and the current status of the CAC apparatus, and subsequently describe the design plan and technical targets for the CAC in SECUF. We will demonstrate the unique advantages of CAC, i.e., excellent pressure homogeneity and large hydrostatic pressure capacity, by summarizing our recent research progresses using CAC. Finally, we conclude by providing some perspectives on the applications of CAC in the related research fields. (topical review — synergetic extreme condition user facility: breakthroughs and opportunities for the research of physical science)
[en] Magnetoresistance and Hall resistance measurements were conducted in the field-induced spin-density-wave (FISDW) phase of (TMTSF)2ReO4 above 1.0 GPa, with an anion ordering specified by . The quantized Hall resistance shows the sequence , with decreasing field that is successfully explained by the “extended standard model”. Consequently, we demonstrate that the difference between the chemical and hydrostatic pressures is linked to the appearance of the peculiar FISDW phase of the TMTSF salts with . (letter)
[en] Radial elastic corrugation of multiwalled carbon nanotubes under hydrostatic pressure is demonstrated by using the continuum elastic theory. Various corrugation patterns are observed under a pressure of several GPa, wherein the stable cross-sectional shape depends on the innermost tube diameter D and the total number N of concentric walls. A phase diagram is established to obtain the requisite values of D and N for a desired corrugation pattern among choices. In all corrugation patterns, the cylindrical symmetry of the innermost tube is maintained even under high external pressure.
[en] A reciprocal equation for the volume dependence of Anderson–Grüneisen parameter has been proposed. This equation has been found to fit the seismic data for the lower mantle region of the Earth. We have developed a new expression for predicting the values of density (volume) dependence of volume thermal expansivity under adiabatic conditions based on the reciprocal equation for the volume dependence of Anderson–Grüneisen parameter. It is found that our relationship fits well the seismic data on volume thermal expansivity for lower mantle corresponding to a wide range of pressures (0–135.75 GPa). These equations thus proposed are found to be consistent with the thermodynamic constraints
[en] Computerized simulations have shown that the transformation of hydrogen gas into metal requires a pressure around 450 GPa. The issue is that the best devices to produce very high pressures are diamond anvils but these anvils broke over 400 GPa. Usually diamond anvils have a plane surface but tests with a toroidal-shaped surface have shown that pressures around 600 GPa can be reached. A cylinder gap, filled with hydrogen, inside a rhenium sheet that is set on the toroidal-shaped surface between the 2 anvils, has allowed the scientists to reach a pressure over 450 GPa. The anvils have been equipped with an infrared beam crossing the hydrogen sample. At 300 Gpa, the hydrogen is solid and the infra-red beam crosses it, at around 425 GPa, the hydrogen sample becomes suddenly opaque to infra-red rays and reflects them which marks the transition of hydrogen to metal state. The decreasing of the pressure shows that the process is reversible: hydrogen recovers its original properties. (A.C.)