ABSTRACT A new custom-designed cooling system is described that was developed for the SAPHiR three-axis multi-anvil press with MA6-6 anvil geometry at the FRM II neutron source in Garching. The system was designed to remove heat from the secondary anvils by flowing a cryogen around custom-designed cooling rings or cooling jackets. Currently, this cryo-system is capable of achieving temperatures of

ABSTRACT The characteristics of hydrostatic stress conditions are discussed and compared with real experimental observations made under high pressure with a diamond-anvil cell. While fluid pressure-transmitting media give a well-defined single stress condition, solid pressure-transmitting media give a variety of stress conditions within the limit of their shear strength under high pressure. Owing to

ABSTRACT In this study, the effects of immobilization and high hydrostatic pressure (HHP) on capsaicin production in cell suspension culture of pepper seeds at different application times were investigated. Callus cultures were obtained from in vitro germinated hypocotyl explants of pepper seedlings and cell suspensions were prepared from calluses. Immobilized cell suspension cultures with calcium

ABSTRACT We report theoretical and experimental investigations on the structures of strontium and magnesium oxalates, and corresponding Raman spectra at high pressure. These systems have shown progress in the generation of CO2 and in the synthesis of energetic doped polymeric carbon monoxide after X-ray irradiation and simultaneous application of high pressure. Density functional perturbation theory

ABSTRACT We applied Kawai-type multi-anvil assemblies (MA6-8) for time-of-flight neutron-diffraction experiments to achieve high-pressures and high-temperatures simultaneously. To achieve sufficient signal intensities, the angular access to the sample was enlarged using slits and tapers on the first-stage anvils. Using SiC-binder sintered diamond for the second-stage anvils that transmits neutrons

ABSTRACT Large-volume cubic presses are widely used in scientific research and industrial applications. However, their pressure capability is often limited to 6 GPa, which severely restricts their applications under extended pressures. In this work, we report a newly designed hybrid cell assembly for cubic presses by embedding six WC pressure-enhancing blocks into the pyrophyllite pressure-transmitting

ABSTRACT We applied Kawai-type multi-anvil assemblies (MA6-8) for time-of-flight neutron-diffraction experiments to achieve high-pressures and high-temperatures simultaneously. To achieve sufficient signal intensities, the angular access to the sample was enlarged using slits and tapers on the first-stage anvils. Using SiC-binder sintered diamond for the second-stage anvils that transmits neutrons

ABSTRACT The solubility of NaCl in water is one of the most important thermo-physical properties. However, the solubility behavior of NaCl in water is poorly understood at high pressure and low temperature. Herein, we performed high pressure neutron diffraction and Raman scattering to investigate the solubility of NaCl in water and the corresponding structural change, respectively. With the pressure

ABSTRACT We have developed a new type of experimental setup utilizing a multi-anvil large volume press and designed for simultaneous measurements of structure-sensitive thermophysical properties (diffraction, electrical resistivity, viscosity). This multi-probe capability was tested on iron alloys at 2 GPa and up to 1750 K. Phase transitions as detected by X-ray diffraction patterns are clearly associated

ABSTRACT Thermoelastic behavior of transition metal boride Os2B3 was studied under quasi-hydrostatic and isothermal conditions in a Paris-Edinburgh cell to 5.4 GPa and 1273 K. In-situ Energy Dispersive X-ray diffraction was used to determine interplanar spacings of the hexagonal crystal structure and the P-V-T data were fitted to a 3rd Order Birch–Murnaghan equation of state with a temperature modification

ABSTRACT Two ultrasonic measurement methods for pressure calibration to 4.4 GPa in a multi-anvil apparatus by measuring the travel times of longitudinal wave as a function of pressure are reported. The first method is to continuously calibrate pressure by combining the measured travel times of Z-cut quartz under hydrostatic pressure with the related equation of state and unit-cell parameters of quartz

ABSTRACT The preparation of SEM samples is a complex and time-consuming process. The present report describes the development of a simple and inexpensive high pressure water freeze fracture method for the preparation of SEM samples from hydrogels without using organic solvents. This method involves two key features. First, the sample and water are frozen with liquid nitrogen in a pressure-resistant

ABSTRACT Life adapts to various environments, including high temperatures and high pressures. The brine shrimp Artemia was used to investigate the tolerance to hydrostatic pressure up to 750 bar. The swimming activity of Artemia nauplii (larval form) decreased as pressure increased, and the activity became null at 400 bar and above. Interestingly, at 300 bar and less, the swimming activity gradually

ABSTRACT The structural transformation of FePO 4 from the trigonal berlinite phase to the orthorhombic CrVO 4 phase has been studied using neutron diffraction at high pressure and high-temperature. The berlinite structure was compressed to a pressure of 5.2(2) GPa and amorphisation observed. Upon annealing at temperatures above 798(28) K the high pressure FePO 4 structure was observed to form. This

ABSTRACT The structural transformation of FePO 4 from the trigonal berlinite phase to the orthorhombic CrVO 4 phase has been studied using neutron diffraction at high pressure and high-temperature. The berlinite structure was compressed to a pressure of 5.2(2) GPa and amorphisation observed. Upon annealing at temperatures above 798(28) K the high pressure FePO 4 structure was observed to form. This

ABSTRACT We report on the feasibility of high pressure neutron scattering in clamp cells at various diffraction and spectroscopy beamlines in the Heinz Maier-Leibnitz Zentrum in Garching (Germany). The cells are compact in order to fit into the existing sample environment devices and to accommodate samples up to about 150 mm³ at pressures above 1 GPa.

ABSTRACT We present the in situ neutron diffraction data of a water and silica mixture at high pressure and temperature. We show initially the formation of ice VI at 1.5 GPa at 290 K in the presence of crystalline SiO2, upon heating we observe its melting at ∼400 K. Upon further warming to 1200 K, we observe melting of the crystalline silica. Upon cooling to 290 K and recovery to ambient pressure,

ABSTRACT Melting of orthorhombic boron silicide B6Si has been studied at pressures up to 8 GPa using in situ electrical resistivity measurements and quenching. It has been found that in the 2.6–7.7 GPa range B6Si melts congruently, and the melting curve exhibits negative slope of −31(2) K/GPa that points to a higher density of the melt as compared to the solid phase. At very high temperatures B6Si

ABSTRACT 3.65 Å-phase (or hydroxide-perovskite), MgSi(OH)6, is a representative of dense hydrous magnesium silicates (DHMS) with maximum water content (up to ∼35 wt.% H2O) and thus is of interest as one of the largest repositories of water among all the known hydrous phases. Sample of 3.65 Å-phase, grown in DIA-type multianvil apparatus, was studied by Raman spectroscopy under pressure up to ∼7 GPa

ABSTRACT By means of comparing molar volumes at reference ambient conditions (298 K, 1.105 Pa) of 160 pressure-driven polymorphic transitions in chalcogenides, germanates, silicates, simple molecular compounds, elemental non-metals and a few metals it is shown that for reconstructive transitions between 0.1 and 150 GPa, mean volume contraction ranges around 11% for about 85% of all examined materials

ABSTRACT Characterization of a new pressure medium Daphne Oil 7575 using a set of three manganin coils, a superconducting temperature of lead and the response of two perpendicular strain-gages down to low temperatures is presented. A complementary study of Daphne Oil 7474 and Daphne Oil 7373 employing identical methods is included as well. Temperature dependence of the solidification point of Daphne

ABSTRACT Among the non-thermal food technologies, high pressure processing (HPP) is currently the most widespread intervention in the juice industry. The study herein was conducted to challenge a wide range of pressure (401–599 MPa) and dwell time (87–313 s) in orange juice processing. The parameters were combined and targeted a minimum of 5-log cycle reductions in a cocktail for the pathogens of reference

ABSTRACT Winter savory is often used in traditional medicine, having several recognized biological properties. This study aimed to evaluate the effect of high pressure-assisted extraction (HPE) and its optimization by response surface methodology to obtain winter savory extracts with a high content of bioactive compounds and high antioxidant activity (the effect of extraction pressure, extraction time

At the 26th AIRAPT conference in 2017, a task group was formed to work on an International Practical Pressure Scale (IPPS). This report summarizes the activities of the task group toward an IPPS ruby gauge. We have selected three different approaches to establishing the relation between pressure (P) and ruby R1-line shift (Δλ) with three groups of optimal reference materials for applying these approaches

ABSTRACT To understand the practical effects of pressure-transmitting media (PTM) on neutron diffraction using Paris–Edinburgh presses, diffraction patterns of MgO were collected to approximately 20 GPa using PTMs of Pb, AgCl, 4:1 methanol–ethanol (ME) mixture with and without heating, N2, and Ar. Hydrostaticity in the sample chamber estimated from the MgO 220 peak width improves in the order of Pb

We tested boron-doped diamond (BDD) synthesized by chemical vapor deposition (CVD) as a heating element in a multi-anvil apparatus. We succeeded in manufacturing BDD into a tubular shape by laser cutting and electric discharging machining. The BDD tube shaped by the electric discharging machining was contaminated by discharging electrode materials (Mo and W), which affected the heating performance

High temperature is of paramount importance in high pressure science. One of the leading tools in this respect is the resistively heated diamond anvil cell (DAC), where the heat is provided by small heaters, positioned close to the diamond/gasket/sample region (internally heated DAC, IHDAC) or by wrapping the DAC body into bigger heaters (externally heated DAC, EHDAC). Although IHDACs can reach sample

The phase transitions and equation of state measurements were carried out on rare earth metal Holmium (Ho) to 282 GPa using toroidal diamond anvils thereby doubling the pressure range to which it has been studied previously. The first set of experiment employed standard beveled diamond anvils utilizing copper as an x-ray pressure standard to 217 GPa. The second set of experiment employed toroidal diamond

The compressibility and effect of pressure on the vibrations of merrillite, Ca9NaMg(PO4)7, were studied by using diamond anvil cell at room temperature combined with in-situ synchrotron X-ray diffraction and Raman spectroscopy up to about 18 and 15 GPa, respectively. The pressure-volume data was fitted by a third-order Birch–Murnaghan equation of state to determine the isothermal bulk modulus as K0

High pressure processing (HPP) and sous vide may increase the shelf-life of high value seafood products without the use of additives. This study investigated the effects of 150MPa or 350MPa for 10min on microbial, sensory, and physicochemical qualities of raw and subsequently sous vide cooked (65°C) lobster tails during 28 days of refrigerated storage. Raw lobster pressurized at 350MPa or sous vide

Elastic stiffness constants, C ijs, of single crystal of NaCl B1 phase have been determined at pressure up to 20 GPa using inelastic x-ray scattering to measure elastic wave velocities and x-ray diffraction to measure densities in the same experimental setup. The Voigt-Reuss-Hill average velocities calculated from the present Cijs are in good agreement with previous ultrasonic measurements of polycrystalline

ABSTRACT Elastic stiffness constants, C ijs, of single crystal of NaCl B1 phase have been determined at pressure up to 20 GPa using inelastic x-ray scattering to measure elastic wave velocities and x-ray diffraction to measure densities in the same experimental setup. The Voigt-Reuss-Hill average velocities calculated from the present Cijs are in good agreement with previous ultrasonic measurements

ABSTRACT A new method for stirring under high pressure conditions has been developed and tested. The key component is a Teflon cell assembly equipped with magnetic stirring function, which is capable to operate across a wide pressure range, up to at least 2 GPa, in a large volume press. The setup enables adjustable stirrer rotation rate and detection of stirring in a sample, e.g. to observe liquid–solid

The quasi-hydrostatic compression of cesium chloride and cesium bromide has been measured with X-ray diffraction up to 141 GPa at 300 K. A cubic to orthorhombic P m 3 ¯ m → P m m a transition, with a ≥10% distortion of lattice parameters, is evidenced in CsBr around 60 GPa. A smaller distortion (∼1.5%) appears in CsCl at the same pressure, followed by a likely transition to a lower symmetry phase which

Quantitative single crystal neutron-diffraction in diamond anvil cells has so far been limited by the neutron flux available at the various neutron sources. As a result, highly precise measurements of the exact position of light elements have not been possible preventing, for example, structural studies of hydrogen and hydrogen bonds under pressure. Here we report experiments carried out on SNAP at

We report experimental determination of compressibility and thermoelasticity for CrN based on in situ high pressure/high temperature synchrotron x-ray diffraction measurements. The pressure-induced cubic-to-orthorhombic phase transition is observed at ∼ 5 GPa in high-quality CrN samples synthesized using a high pressure reaction route. Equation of state, bulk modulus and axial compressibility of this

A systematic study of orthorhombic phase formation at ambient conditions beyond a critical concentration of dopant Tantalum (Ta) in HfO 2 is reported. The effect on the path of structural evolution due to Ta doping in HfO 2 was also investigated. Studies on Ta-doped HfO 2 samples and their path of structural evolution under compression have significant implications for materials undergoing β-decay

Thermal conductivities of planetary materials under extreme conditions are important input parameters for modeling planetary dynamics such as accretion, geodynamo and magnetic field evolution, plate tectonics, volcanism-related processes etc. However, direct experimental measurements of thermal conductivity at extreme conditions remain challenging and controversial. Here we propose a new technique

The crystal structures, lattice dynamics, mechanical, electronic properties, and electron–phonon coupling of Th3N4 under environmental conditions and high pressures have been studied by merging first-principles calculations and particle-swarm optimization algorithm. Four structures are identified for Th3N4, including the R3¯m, I4¯3d, R3¯, and C2/m phases, in which the I4¯3d, R3¯, and C2/m phases are

The pressure stability of the first hydration shell of Y 3+ ions in aqueous solution has been investigated by means of extended x-ray absorption fine-structure spectroscopy at the yttrium K-edge for hydrostatic pressures up to 4.5 kbar and concentrations between 1 M and 2.5 M. We find approximately 8.4 water molecules surrounding the yttrium cation at a mean distance of 2.370 Å at ambient conditions

A new high pressure cell for neutron diffraction experiments using nano-polycrystalline anvils is presented. The cell design, off-line pressure generation tests and a gas-loading procedure for this cell are described. The performance is illustrated by powder neutron diffraction patterns of ice VII to ∼82 GPa. We also demonstrate the feasibility of single crystal neutron diffraction experiments of Fe3O4

A new opposed type double-stage large volume cell has been developed to compress large volume samples to more than 100 GPa (Mbar) pressure. A pair of second-stage diamond anvils is introduced into the first-stage Paris–Edinburgh press. The double-stage large volume cell allows the generation of ultrahigh pressures using a large culet diameter of the second-stage diamond anvils (diameters of 0.5–1.2 mm)

Here we report a novel route for synthesizing nano-polycrystalline diamond (NPD) using stearic acid (C18H36O2) as a starting material under high pressure and high temperature. The obtained NPD shows a transparent dark-yellowish color similar to the standard NPD synthesized from graphite and consists of extremely fine diamond grains (∼10 nm). The temperature required for the present synthesis of pure

Current anvil designs and problems associated with various efforts to generate static high pressures beyond the limit of conventional diamond anvil cells (DACs) (∼400 GPa) are reviewed. Pressures of up to 1 TPa have been reported by one research group using the double-stage DAC (ds-DAC) technique, but no other research group has successfully reproduced this high pressure result. Some research groups

Deep-ultraviolet continuous-wave photoluminescence spectroscopy is performed for nano-polycrystalline diamond (NPD) synthesized by a high pressure high-temperature technique. NPD exhibits clear deep-ultraviolet emissions, which originate from intrinsic excitonic transitions assisted by a momentum-conserving phonon with a photon. Surprisingly, the peak emission energy is about 30 meV higher than that

We present the element-selective local structure analysis of ferromagnetic Fe 65Ni 35 Invar alloy and Fe 72Pt 28 alloy under high pressures as a recent application of nano-polycrystalline diamond (NPD) to extended X-ray absorption fine structure (EXAFS). The Invar effect is a phenomenon where thermal expansion becomes nearly zero in a wide range of temperatures. Fe 72Pt 28 is an alloy exhibiting negative

We present the first application of double-stage diamond anvil cells (ds-DACs) to X-ray absorption spectroscopy (XAS) of Rhenium (Re) metal. By using highly stable and sub-micron sized X-ray beam, XAS spectra were successfully observed at the L2,3-edges from the sample encapsulated in the small space between the second-stage anvils. The pressure generation exceeding 300 GPa was evaluated by the pressure-induced

We investigated the optical properties (absorption, luminescence and Raman spectra) of nanopolycrystalline diamond (NPD) aiming at exploring its capabilities as a pressure sensor and as a pressure-cell anvil for combined X-ray/neutron and optical studies. Notably, we analysed the Raman peak shift and broadening with pressure using a Moissanite Anvil Cell (MAC). The results are compared with those obtained

Nano-polycrystalline diamond (NPD) with various grain sizes has been synthesized from glassy carbon at pressures 15–25 GPa and temperatures 1700–2300°C using multianvil apparatus. The minimum temperature for the synthesis of pure NPD, below which a small amount of compressed graphite was formed, significantly increased with pressure from ∼1700°C at 15 GPa to ∼1900°C at 25 GPa. The NPD having grain

A high-pressure cell for in-situ single-crystal neutron diffraction was developed. The cell uses nano-polycrystalline diamond anvils in a tubular load frame made of bulk metallic glass which is highly transparent to neutrons and does not produce Bragg reflections. Diffraction peaks from a sample can be measured from almost any direction and the simple geometry of the cell allows accurate attenuation

High pressure energy-dispersive X-ray absorption spectroscopy is a valuable structural technique, especially, when combined with a nano-polycrystalline diamond anvil cell. Here we present recent results obtained using the dispersive setup of the ODE beamline at SOLEIL synchrotron. The effect of pressure and temperature on the X-ray induced photoreduction is discussed on the example of nanocrystalline

Nano-polycrystalline diamonds (NPDs) have become fundamental tools for cutting-edge X-ray absorption spectroscopy (XAS) studies at high P/T conditions that opened up new research directions by overcoming previous limitations. Indeed, NPDs yield a continuous and weak X-ray background signal which enables the collection of high-quality XAS data of materials compressed in diamond anvil cells. This is

In this work, we use extended X-ray absorption fine structure (EXAFS) data collected using nano-polycrystalline diamond anvil cell to study the atomic arrangement in Zr–Cu metallic glass in high pressure (HP) conditions. To reveal the microscopic details of stress accommodation mechanism, we performed molecular dynamics (MD) simulations of the HP atomic arrangement. By comparing the experimental and

The use of nanopolycrystalline diamond has allowed a systematic study on deformation of polycrystalline diamond composites (PCDCs). Bulk PCDCs samples containing either Co or SiC as a binding agent were deformed under high pressure and temperature to strains up to 18% at strain rates ∼10−5 s−1. All samples exhibit strong work hardening. The strength of PCDCs depends on the amount and type of binding

Data-driven exploration for pressure-induced superconductors was performed based on the high-throughput first-principles screening of electronic band structures. In the screening conditions, we focused on the characteristics including a narrow band gap, flat band feature, and possibility of metallization under high pressure. The 27 promising compounds were screened out from the database of Atomwork

Both micro-paired and conical support type double-stage diamond anvil cells (ds-DAC) were tested using a newly synthesized ultra-fine nano-polycrystalline diamond (NPD). Well-focused X-ray sub-micron beam and the conically supported 2nd stage anvils (micro-anvils) with 10 μm culet enable us to obtain good quality X-ray diffraction peaks from the sample at around 400 GPa. The relationship between confining

Generation of high pressure is a key to the investigation of the interior of the Earth. The Kawai-type multianvil apparatus (KMA) has been widely used in the fields of Earth science and material science. In conventional KMA, tungsten carbide (WC) has been used as the second stage anvil material. However, attainable pressure is limited to ∼70 GPa even if newly developed WC is used. Recently, on the

(2020). A brief history of nano-polycrystalline diamond. High Pressure Research: Vol. 40, Nano-Polycrystalline Diamond: Synthesis and applications, pp. 1-2.

Obtaining both high hardness and toughness is a challenge in B4C-nano-adhesive composites. Solving the inhomogeneous distribution of nano-adhesives in B4C and forming the chemical bonding at grain boundary is an effective method. Here, we reported that the uniform distribution of titanium diboride (TiB2)-reinforced B4C composites synthesized by high-pressure and high temperature (HPHT). It is found

TiC-MgO composite was developed as a heating element for X-ray study in the multi-anvil high pressure apparatus. We synthesized TiC-MgO blocks (50–70 wt.% of TiC) by compression in a cold isostatic press followed by baking in a gas flow furnace. Heaters of tubular shape were manufactured from the synthesized blocks either by lathe or numerically controlled milling machine. The so-produced heating elements