The membrane diamond anvil cell

Abstract

A new design for a diamond anvil cell is described. Its main characteristic is that the force on the piston is generated by pressurized helium. Two of its main qualities are illustrated on recent measurements.     

金刚石压腔蛇纹石原位拉曼光谱研究

在金刚石压腔中,运用激光拉曼光谱技术对高压下蛇纹石矿物结构及其稳定性进行了原位观测与研究。实验获得蛇纹石在常温下从0.1～5 140MPa的拉曼光谱数据。研究发现,蛇纹石低频拉曼谱峰388,471,692和705cm-1随压力增加有规律地向高频偏移;层内羟基3 664cm-1峰和层间羟基3 696cm-1峰与压力呈明显的正相关性。层内羟基3 664cm-1峰随压力变化的斜率为3.3cm-1.GPa-1,层间羟基3 696cm-1峰在2.0GPa时斜率由8.3cm-1.GPa-1变为1.1cm-1.GPa cm-1。在实验温压条件下,蛇纹石未发生脱水作用。     

Synthesis experiments on B-Sb,Ge-Sb,and Xe-Pd systems using a laser heated diamond anvil cell

Abstract

In an effort to synthesize B-Sb, Ge-Sb and Xe-Pd compounds under high pressure, the respective system was laser-heated in a diamond anvil cell at temperatures above 2500 K and up to a maximum pressure of 51 GPa. The product was characterized by X-ray diffraction using rotating anode and synchrotron radiation X-ray sources. No reaction was observed in any of these systems up to pressures of 32, 20 and 51 GPa, respectively. In the case of Ge-Sb, new peaks were observed in the pressurequenched samples, but they were identified with the known metastable phases of Ge. In this regard our results are contrary to the earlier work on Ge-Sb.     

Data-driven exploration for pressure-induced superconductors using diamond anvil cell with boron-doped diamond electrodes and undoped diamond insulating layer

ABSTRACT

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 for the candidates of new pressure-induced superconductors. Among the candidates, we actually synthesized three compounds in a single crystal, and all candidates exhibited the pressure-induced superconductivity. For the in-situ electrical transport measurements, we developed a novel configuration of diamond anvil cell with boron-doped diamond electrodes and an undoped diamond insulating layer. The discovered new pressure-induced superconductors via the data-driven approach and the developed diamond anvil cell were summarized in this paper.     

X-ray transmission properties of intelligent anvils in diamond anvil cells

High-pressure and/or high-temperature analysis of geo- and material science samples routinely employs diamond anvil cells (DACs) as a research instrument. In particular, DACs allow for various in situ characterizations (e.g. Raman and Fourier transform infra red spectroscopies, X-ray diffraction (XRD), X-ray spectroscopy including fluorescence (XRF) and absorption (XAS)) at elevated pressure and temperature. The measurement of pressure (P) and/or temperature (T) in the sample chamber is crucial, but not always accurate, more specifically in the case of low-pressure applications (a few GPa). The development of modified diamonds (intelligent anvils ‘i-anvils’) adapted to a new generation of DACs (intelligent diamond anvil cells: iDAC) can contribute to solve this problem, as the diamond itself serves as the PT sensor, being prepared, for example, by high-energy ion implantation [H. Bureau, M. Burchard, S. Kubsky et al., This volume (2006).] on a micrometric scale. Several most interesting measurement methods used with DACs are based on X-ray techniques (e.g. XRF, XRD, XAS). We present the first results of X-ray transmission measurements with iDACs, performed at the hard-X-ray microfocus beamline ID22 at the ESRF (European Synchrotron Radiation Facility), Grenoble, France. Sensor response to intense irradiation as a function of X-ray energy (E _ph∈10;18.1 Burchard, M., Zaitsev, A. M. and Maresh, W. 2003. Rev. Sci. Instr., 74: 1263–1266.  [Google Scholar] keV) was investigated. The values of the sensor were found to be independent of the irradiation in the investigated energy range and thus validate the use of these sensors for precise and reliable measurements on a wide range of applications with high-energy synchrotron radiation. No influence of the sensor on the X-ray transmission properties of the anvil has been found.     

Finite-element modeling of stresses and strains in a diamond anvil cell device: case of a diamond-coated rhenium gasket

The stresses and strains in a diamond anvil cell device were investigated using a finite-element code NIKE2D for the case of an ultra-hard composite gasket material. The pressure distribution in a diamond-coated rhenium gasket was measured by the energy dispersive diffraction technique to 213 GPa and compared with the finite-element modeling results. We examine various models for the mechanical properties of diamond-coated rhenium gasket as well as for diamond failure for shear stresses exceeding 100 GPa. The elastic and plastic properties of gasket were varied such that a good agreement between the experimentally measured pressure distribution and the computational pressure profiles were obtained. As a result, we obtained the effective Young’s modulus, Poisson’s ratio, yield stress for indented gasket, linear hardening modulus, and hardening parameter value for this layered ultra-hard composite gasket material. Future diamond design strategies for attainment of extreme high pressures using ultra-hard gasket materials are also discussed.     

A convenient dynamic loading device for studying kinetics of phase transitions and metastable phases using symmetric diamond anvil cells

We have designed and implemented a novel DLD for controlling pressure and compression/decompression rate. Combined with the use of the symmetric diamond anvil cells (DACs), the DLD adopts three piezo-electric (PE) actuators and three static load screws to remotely control pressure in accurate and consistent manner at room temperature. This device allows us to create different loading mechanisms and frames for a variety of existing and commonly used diamond cells rather than designing specialized or dedicated diamond cells with various drives. The sample pressure compression/decompression rate that we have achieved is up to 58.6/43.3?TPa/s, respectively. The minimum of load time is less than 1?ms. The DLD is a powerful tool for exploring the effects of rapid (de)compression on the structure of materials and the properties of materials.     

In situ mapping of high-pressure fluids using hydrothermal diamond anvil cells

We present new results combining high pressures and temperatures attainable in a diamond anvil cell with in situ synchrotron radiation induced micro-X-ray fluorescence measurements. Hydrothermal diamond anvil cells experiments have been performed by measuring the partitioning of Pb between aqueous fluids (pure water or NaCl-enriched water) and hydrous silicate melts of haplogranite composition using synchrotron X-ray fluorescence. The in situ measurements were performed in the range 0.3–1.2 GPa and 730–850 ^°C both in the aqueous fluid and in the silicate melts being in equilibrium. Pb is strongly partitioned into high-pressure–temperature hydrous melts when Cl is present in either the hydrous melt or the aqueous fluid. Moreover, our comparisons of in situ results with post-mortem results show that significant changes take place during rapid quenching especially when samples are small (few hundred of microns in diameter). Water exsolution is induced by the quench in the silicate melt showing the high mobility of Pb which immediately partitions into the water vapor phase during the quench. The current in situ approach offers thus a pertinent complementary method to the classical experimental petrology investigations.     

Miniature cryogenic diamond anvil cell

Abstract

The miniature cryogenic diamond anvil described previously [D.J. Dunstan and W. Scherrer, Rev. Sci. Instrum. 59, 627 (1988)] has been modified to facilitate its use, and has been taken to 26GPa. The modifications are described here, together with some details of operation.     

The numerical modelling of the stress-strained state of diamond anvil cell components

Abstract

The method of numerical modelling of the behaviour of main components (anvils and deformable gasket) in diamond anvil cells (DAC) in the process of pressure generation has been developed and realized in the form of programs packages. The optimization of the geometry and loading conditions for an anvil was conducted in line with the multilevel factor plan of major effects (MFPME). A combination of optimizing factors allowing to obtain the theoretically predicted pressure of 465 GPa has been found, the value that by 2.7 times higher than that obtained on anvils at an analogous external pressure distribution [1] and the same diamond strength.

FEM     

A new dimension in structural biology: fully fledged high-pressure macromolecular crystallography

The amount of accurate crystallographic data currently available on macromolecular structures at high pressure is extremely limited, mainly due to the lack of appropriate instrumentation and X-ray sources. A technical breakthrough has been achieved with a set-up at the ESRF ID30 beamline equipped with a diamond anvil cell and a large imaging plate, and taking advantage from undulators providing a quasi-plane wave of ultrashort wavelength X-rays. The accessible pressure range is increased by nearly one order of magnitude with respect to beryllium cells. A nearly perfect long-range order is preserved in protein and virus crystals compressed below the denaturation pressure. The quality of diffraction data collected at high pressure can meet usual standards, especially in the case of high symmetry space groups.

An overview of main results and ongoing studies is given, including the 7?kbar structure of hen egg-white lysozyme refined at 1.6?Å resolution and structural investigations of cowpea mosaic virus (CPMV), the first macromolecular assembly investigated at high pressure by single crystal X-ray diffraction. The ordering effect of high pressure on the molecular packing of disordered P23 crystals was highlighted. The 2.8?Å resolution structure of CPMV at 3.3?kbar was fully refined using high completeness data collected on pressure-ordered I23 crystals.     

X-ray absorption spectroscopy under high pressures in diamond anvil cells

Abstract

Although potentially extremely important for understanding the high-pressure microscopic behaviour of materials, over the years the area of high-pressure EXAFS in particular using diamond anvil cells has proved to be technically difficult. This has significantly hampered its development. The interference of X-ray dimaction from the diamonds in the diamond anvil cell with the absorption signal has proved to be a challenging problem to tackle, restricting the use of high-pressure EXAFS to energies below about 11 key Below 11 keV however the technique is also limited due to absorption of incident X-rays by the diamonds making it virtually impossible to conduct X-ray absorption experiments below about 9keV In this paper we describe in detail the methodology for scanriirig high-pressure EXAFS in diamond anvil cells and examine the origins of the associated problems and ways of dealing with them. We also demonstrate that it is possible to extend the useful range of studied absorption edges from 7keV up to at least 30keV This brings about new opportunities for high pressure EXAFS using diamond anvil cells.     

How to detect melting in laser heating diamond anvil cell

Research on the melting phenomenon is the most challenging work in the high pressure/temperature field. Until now,large discrepancies still exist in the melting curve of iron, the most interesting and extensively studied element in geoscience research. Here we present a summary about techniques detecting melting in the laser heating diamond anvil cell.     

Method of low-temperature optical measurements with diamond anvil cells

Abstract

Constructions of a cryogenic diamond anvil system with mechanical clamping press and helium pressure medium for microscopic optical studies are described. Low temperature nonmagnetic cells ø40 and ø20 mm have been developed. GaP samples doped with S, Te and isoelectronic impurities N, NN have been investigated up to 20 GPa at 1.5-300K.     

Compression and shear on lead in a rotational diamond anvil cell

By application of large plastic shear on a lead sample in a rotational diamond anvil cell, we studied the pressure self-multiplication and the stress deviation phenomena, along with the consequential effects on a phase transformation of lead. It is indicated that pressure can be promoted by the gradual addition of shear. The stress deviation in the sample along different Chi angles is minimal and within the systematic error range. It is thus specified that a quasi-hydrostatic condition is generated in the sample chamber. Moreover surprisingly, under such shear-controlled pressure elevation, the lead fcc-to-hcp phase transformation pressure is found to initiate and complete, respectively, at 12.8 and 18.5?GPa, which is identical to those observed in hydrostatic compressions. The phenomena of the so-launched quasi-hydrostatic pressure, the self-multiplication, along with the consequential effects on the phase transformation properties by shear at pressures are expected to lead to further understanding of materials as well as to potential new technologies at extremes.     

Resistively heated,high pressure,membrane and screw driven diamond anvil cell

ABSTRACT

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 temperatures higher than 1000?K, they are difficult to handle and the heater/diamond/gasket/sample region may be affected by strong thermal gradients potentially hindering accurate temperature measurements. Here we present a novel EHDAC, which overcomes these issues by uniquely joining: (i) high mechanical precision for multi-Mbar, (ii) high temperature alloys for operating to 1000?K, (iii) membrane or screw driven, easily switchable between each other, (iv) operation into a vacuum chamber, (v) uniform temperature, (vi) facile handling, and (vii) possibility to add internal heaters for achieving even higher temperatures.     

Anvil design for slip-free high pressure deformation experiments in a rotational diamond anvil cell

A rotational diamond anvil cell is the most suitable deformation apparatus with which to investigate the rheological properties of deep-Earth materials at pressures similar to those found in the lower mantle and core. However, slip between the sample and piston is still a problem, since the slip prevents the attainment of a constant strain rate and interferes with the uniform deformation of a sample. In this paper, we report that using a diamond anvil with deep grooves results in a marked improvement in the coupling between the sample and the diamond anvils.     

Kinetic study of phase transformation of n-octane using hydrothermal diamond anvil cell

A kinetic study of phase transformation of n-octane has been performed using a hydrothermal diamond anvil cell. The results show that pressure has a negative effect on the solid–liquid reaction rate. The increase of pressure can accelerate the liquid–solid transformation rate. Upon the liquid–solid transformation, the light transmittance showed a decreased trend with time in the early stage, which was caused by the formation of a large quantity of crystal nuclei. In the later stage, the light transmittance almost remained the same, thus indicating a growth stage of crystal nuclei. The activation volume yields a value of 2.16×10^?5 and –1.35×10^?5 m³/mol for the solid–liquid and liquid–solid transformations. Based on the obtained activation energy, the solid–liquid transformation is dominated by the interfacial reaction and diffusion, and the liquid–solid transformation is controlled by diffusion. This technique is an effective and powerful tool for the transformation kinetics study of n-octane.     

一种以压力一维均匀分布为特征的长条形对顶压砧

针对圆形端面平面对顶压砧装置中压力梯度大的问题, 本文设计了一种长条形端面的平面对顶压砧, 相应的封垫也改为长条形. 原理分析表明: 这种压砧可在沿长条形中心线的狭长区域内产生均匀分布的高压力. 本文采用长20 mm宽5 mm长条形端面的硬质合金压砧配合叶腊石封垫进行压力标定, 实验结果显示: 这种装置可产生10 GPa以上的高压, 在长条形中心线上至少12 mm长度范围内的不同位置上产生的压力基本一致, 在2.55 GPa压力时测量偏差小于2.0%, 在7.7 GPa时测量偏差小于3.6%. 这种特点很有利于对细长样品进行精确的高压物性测量.     

Effect of deformation of diamond anvil and sample in diamond anvil cell on the thermal conductivity measurement

Studies show that the sample thickness is an important parameter in investigating the thermal transport properties of materials under high-temperature and high-pressure (HTHP) in the diamond anvil cell (DAC) device. However, it is an enormous challenge to measure the sample thickness accurately in the DAC under severe working conditions. In conventional methods, the influence of diamond anvil deformation on the measuring accuracy is ignored. For a high-temperature anvil, the mechanical state of the diamond anvil becomes complex and is different from that under the static condition. At high temperature, the deformation of anvil and sample would be aggravated. In the present study, the finite volume method is applied to simulate the heat transfer mechanism of stable heating DAC through coupling three radiative-conductive heat transfer mechanisms in a high-pressure environment. When the temperature field of the main components is known in DAC, the thermal stress field can be analyzed numerically by the finite element method. The obtained results show that the deformation of anvil will lead to the obvious radial gradient distribution of the sample thickness. If the top and bottom surfaces of the sample are approximated to be flat, it will be fatal to the study of the heat transport properties of the material. Therefore, we study the temperature distribution and thermal conductivity of the sample in the DAC by thermal-solid coupling method under high pressure and stable heating condition.