scholarly journals In situ micro-FTIR spectroscopic investigations of synthetic ammonium phengite under pressure and temperature

2020 ◽  
Vol 32 (5) ◽  
pp. 469-482
Author(s):  
Nada Abdel-Hak ◽  
Bernd Wunder ◽  
Ilias Efthimiopoulos ◽  
Monika Koch-Müller
Keyword(s):  
Ambient Temperature ◽  
Ambient Pressure ◽  
Local Symmetry ◽  
Short Term ◽  
Stability Range ◽  
Piston Cylinder ◽  
In Situ Experiments ◽  
Diamond Anvil ◽  
Kinetic Effects

Abstract. Phengite is known to be an important mineral in the transport of alkalis and water to upper mantle depths. Since ammonium (NH4+) can substitute for K+ in K-bearing minerals, phengite is thus a potential host to transport nitrogen into the mantle. However, the temperature and pressure conditions at which devolatilisation of NH4-bearing phengite occurs are not well constrained. In this study, NH4-phengite (NH4)(Mg0.5Al1.5)(Al0.5Si3.5)O10(OH)2 was synthesised in piston-cylinder experiments at 700 ∘C and 4.0 GPa. Its devolatilisation behaviour was studied by means of in situ micro-FTIR (Fourier transform infrared) spectroscopy under low and high temperatures from −180 up to 600 ∘C at ambient pressure using a Linkam cooling–heating stage and pressures up to 42 GPa at ambient temperature in diamond anvil cell (DAC) experiments. In addition to these short-term in situ experiments, we performed quenched experiments where the samples were annealed for 24 h at certain temperatures and analysed at room conditions by micro-FTIR spectroscopy. Our results can be summarised as follows: (1) an order–disorder process of the NH4+ molecule takes place with temperature variation at ambient pressure; (2) NH4+ is still retained in the phengite structure up to 600 ∘C, and the expansion of the NH4+ molecule with heating is reversible for short-term experiments; (3) kinetic effects partly control the destabilisation of NH4+ in phengite; (4) ammonium loss occurs at temperatures near dehydration; (5) NH4+ in phengite is apparently distorted above 8.6 GPa at ambient temperature; and (6) the local symmetry of the NH4+ molecule is lowered/descended/reduced by increasing pressure (P) or decreasing temperature (T), and the type and mechanism of this lowered symmetry is different in both cases. The current study confirms the wide stability range of phengite and its volatiles and thus has important implications for the recycling of nitrogen and hydrogen into the deep Earth. Moreover, it is considered as a first step in the crystallographic determination of the orientation of the NH4+ molecule in the phengite structure.

Structure–melting relations in isomeric dibromobenzenes

2014 ◽  
Vol 70 (3) ◽  
pp. 492-497 ◽  
Author(s):  
Kamil F. Dziubek ◽  
Andrzej Katrusiak
Keyword(s):  
Melting Point ◽  
Ambient Pressure ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Diamond Anvil ◽  
Higher Temperature

1,4-Dibromobenzene melts at a considerably higher temperature than the 1,2- and 1,3-isomers. This melting-point difference is consistent with the molecular symmetry, as described by Carnelley's rule, and with the frequency of Br...Br halogen bonds. The lowest melting point of 1,3-dibromobenzene correlates with its two symmetry-independent molecules, indicating their inability to pack closely. Single crystals of 1,2- and 1,3-dibromobenzene have been grown under isochoric conditions in a diamond–anvil cell and at isobaric conditions in a glass capillary. Their structures have been determinedin situby X-ray diffraction. At 295 K 1,2-dibromobenzene crystallizes at 0.2 GPa as orthorhombic, space groupPbca,Z′ = 1, and 1,3-dibromobenzene at 0.3 GPa as orthorhombic, space groupP212121,Z′ = 2. The same crystal phases are formed at ambient pressure by freezing these liquids below 256.15 and 248.45 K, respectively. The third isomer, 1,4-dibromobenzene, is a solid at room temperature and crystallizes as monoclinic, space groupP21/a. Striking relations between the structures and melting points of the corresponding dibromobenzene and dichlorobenzene isomers have been discussed.

On the use of diamond as a pressure calibrant for near-infrared FT–Raman microspectroscopy at high pressures

1995 ◽  
Vol 73 (7) ◽  
pp. 1019-1022 ◽  
Author(s):  
Ross D. Markwell ◽  
Ian S. Butler
Keyword(s):  
Near Infrared ◽  
Phonon Mode ◽  
High Pressures ◽  
Ambient Pressure ◽  
Raman Microspectroscopy ◽  
Near Ir ◽  
Ft Raman Spectroscopy ◽  
Diamond Anvil ◽  
Ft Raman

The pressure-induced shift of the Raman-active t2g phonon mode of the diamond windows in a commercial diamond-anvil cell, located at l332.5 cm−1 at ambient pressure, can be used as an in situ calibrant for near-IR FT–Raman microspectroscopy at high pressures. The measured pressures are considered to be accurate to within ±2 kbar throughout the 4–45 kbar range for which the associated pressure (P, kbar) vs. wavenumber (v, cm−1) relationship is P = 6.66v − 1335.9. Keywords: FT–Raman spectroscopy, diamond, high pressures.

High Pressure Synthesis of Solid State Materials

1996 ◽  
Vol 453 ◽  
Author(s):  
Paul F. Mcmillan
Keyword(s):  
High Pressure ◽  
High Hardness ◽  
New Materials ◽  
Crystalline Materials ◽  
High Pressure Synthesis ◽  
Piston Cylinder ◽  
Diamond Anvil ◽  
Pressure Synthesis ◽  
Temperature Work

AbstractWithin the ASU MRSEC, we are using a combination of high pressure synthesis techniques (multi-anvil, piston cylinder), combined with in situ studies in diamond anvil cells, and ab initio calculations, to prepare a range of new materials at high pressure, and to study their physical properties under extreme conditions of pressure and temperature. Work in progress includes experiments on nitrides, particularly glasses and crystalline materials based in the P3N5-HPN2-PON system, silicate and germanate perovskites and related vanadates and niobates, and high hardness materials in the B-C-N-0 system. Some of our recent results are presented.

In Situ Raman Study of Liquid Water at High Pressure

2018 ◽  
Vol 72 (6) ◽  
pp. 847-852 ◽  
Author(s):  
Alexandr V. Romanenko ◽  
Sergey V. Rashchenko ◽  
Sergey V. Goryainov ◽  
Anna Yu Likhacheva ◽  
Andrey V. Korsakov
Keyword(s):  
High Pressure ◽  
Liquid Water ◽  
Raman Band ◽  
Ambient Pressure ◽  
Pressure Shift ◽  
Diamond Anvil ◽  
Gaussian Decomposition ◽  
The Difference ◽  
Reported Data

A pressure shift of Raman band of liquid water (H2O) may be an important tool for measuring residual pressures in mineral inclusions, in situ barometry in high-pressure cells, and as an indicator of pressure-induced structural transitions in H2O. However, there was no consensus as to how the broad and asymmetric water Raman band should be quantitatively described, which has led to fundamental inconsistencies between reported data. In order to overcome this issue, we measured Raman spectra of H2O in situ up to 1.2 GPa using a diamond anvil cell, and use them to test different approaches proposed for the description of the water Raman band. We found that the most physically meaningful description of water Raman band is the decomposition into a linear background and three Gaussian components, associated with differently H-bonded H2O molecules. Two of these components demonstrate a pronounced anomaly in pressure shift near 0.4 GPa, supporting ideas of structural transition in H2O at this pressure. The most convenient approach for pressure calibration is the use of “a linear background + one Gaussian” decomposition (the pressure can be measured using the formula P (GPa) = −0.0317(3)·ΔνG (cm−1), where ΔνG represents the difference between the position of water Raman band, fitted as a single Gaussian, in measured spectrum and spectrum at ambient pressure).

scholarly journals Synthesis of Manganese Mononitride with Tetragonal Structure under Pressure

Crystals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 511
Author(s):  
Dajian Huang ◽  
Caoping Niu ◽  
Bingmin Yan ◽  
Bo Gao ◽  
Lailei Wu ◽  
...  
Keyword(s):  
High Pressure ◽  
Phase Space ◽  
Laser Heating ◽  
Diamond Anvil Cell ◽  
Ambient Pressure ◽  
Tetragonal Structure ◽  
Metal Nitrides ◽  
Transition Metal Nitrides ◽  
Diamond Anvil

The exploration of the vast phase space of transition metal nitrides is critical for discovering novel materials and potential technological applications. Manganese mononitride with a tetragonal structure (space group I4/mmm) was synthesized in a laser-heating diamond anvil cell, which could be quenched to ambient pressure. The bulk modulus of 173 GPa was measured using in situ high-pressure diffraction, and the axial compressibility shows that, under pressure, the a direction is much more compressible than the c direction in tetragonal MnN. DFT results with correction of the on-site repulsion (GGA + U) confirm that tetragonal MnN is energetically stable and antiferromagnetic. This study highlights the need to include on-site repulsion to understand 3d metal nitrides.

scholarly journals A System for Retrieval and Incubation of Benthic Sediment Cores at In Situ Ambient Pressure and under Controlled or Manipulated Environmental Conditions

2017 ◽  
Vol 34 (5) ◽  
pp. 983-1000 ◽  
Author(s):  
Keith Jackson ◽  
Ursula Witte ◽  
Stewart Chalmers ◽  
Erik Anders ◽  
John Parkes
Keyword(s):  
Deep Sea ◽  
Experimental Approach ◽  
Low Cost ◽  
Ambient Pressure ◽  
Sediment Cores ◽  
Biogeochemical Processes ◽  
Physiological Changes ◽  
The Core ◽  
In Situ Experiments

AbstractThe investigation of benthic biodiversity and biogeochemical processes in the deep sea is complicated by the need to conduct experiments at in situ pressures. Recovery of sediment samples to the surface without maintaining full-depth ambient pressure may damage the organisms that are of interest or cause physiological changes that could influence the processes being studied. It is possible to carry out in situ experiments using remotely operated vehicles (ROVs) or lander systems. However, the costs and complexity of ROV operations are significant and, for both ROVs and landers, the complexity and repeatability of the experiments are subject to the limitations imposed by these platforms. A system is described—the Multi-Autoclave Corer Experiment (MAC-EXP)—that has been developed with the aim of offering a new experimental approach to investigators. The MAC-EXP system is designed to retrieve sediment cores from depths down to 3500 m and to seal them into pressure chambers before being recovered so that they are maintained at their normal ambient pressure. After recovery the core chambers can be connected to a laboratory incubation system that allows for experimentation on the sediment without loss of pressure and under controlled conditions of temperature and oxygen concentration. The system is relatively low cost when compared to ROV systems and can be deployed using methods and equipment similar to those used for routine deployments of small unpressurized multicorers. The results of sea trials are detailed.

scholarly journals In situdefect annealing of swift heavy ion irradiated CeO2and ThO2using synchrotron X-ray diffraction and a hydrothermal diamond anvil cell

2015 ◽  
Vol 48 (3) ◽  
pp. 711-717 ◽  
Author(s):  
Raul I. Palomares ◽  
Cameron L. Tracy ◽  
Fuxiang Zhang ◽  
Changyong Park ◽  
Dmitry Popov ◽  
...  
Keyword(s):  
Ion Irradiation ◽  
Ambient Pressure ◽  
Heavy Ion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Measurement Capability ◽  
Swift Heavy Ion ◽  
Diamond Anvil ◽  
Defect Recovery

Hydrothermal diamond anvil cells (HDACs) provide facile means for coupling synchrotron X-ray techniques with pressure up to 10 GPa and temperature up to 1300 K. This manuscript reports on an application of the HDAC as an ambient-pressure sample environment for performingin situdefect annealing and thermal expansion studies of swift heavy ion irradiated CeO2and ThO2using synchrotron X-ray diffraction. The advantages of thein situHDAC technique over conventional annealing methods include rapid temperature ramping and quench times, high-resolution measurement capability, simultaneous annealing of multiple samples, and prolonged temperature and apparatus stability at high temperatures. Isochronal annealing between 300 and 1100 K revealed two-stage and one-stage defect recovery processes for irradiated CeO2and ThO2, respectively, indicating that the morphology of the defects produced by swift heavy ion irradiation of these two materials differs significantly. These results suggest that electronic configuration plays a major role in both the radiation-induced defect production and high-temperature defect recovery mechanisms of CeO2and ThO2.

scholarly journals Laboratory measurements of HDO/H2O isotopic fractionation during ice deposition in simulated cirrus clouds

2017 ◽  
Vol 114 (22) ◽  
pp. 5612-5617 ◽  
Author(s):  
Kara D. Lamb ◽  
Benjamin W. Clouser ◽  
Maximilien Bolot ◽  
Laszlo Sarkozy ◽  
Volker Ebert ◽  
...  
Keyword(s):  
Hydrological Cycle ◽  
Isotope Effects ◽  
Isotopic Fractionation ◽  
Cirrus Clouds ◽  
Polar Regions ◽  
Small Surface ◽  
Near Surface ◽  
In Situ Experiments ◽  
Kinetic Effects

The stable isotopologues of water have been used in atmospheric and climate studies for over 50 years, because their strong temperature-dependent preferential condensation makes them useful diagnostics of the hydrological cycle. However, the degree of preferential condensation between vapor and ice has never been directly measured at temperatures below 233 K (−40 °C), conditions necessary to form cirrus clouds in the Earth’s atmosphere, routinely observed in polar regions, and typical for the near-surface atmospheric layers of Mars. Models generally assume an extrapolation from the warmer experiments of Merlivat and Nief [Merlivat L, Nief G (1967) Tellus 19:122–127]. Nonequilibrium kinetic effects that should alter preferential partitioning have also not been well characterized experimentally. We present here direct measurements of HDO/H2O equilibrium fractionation between vapor and ice (αeq) at cirrus-relevant temperatures, using in situ spectroscopic measurements of the evolving isotopic composition of water vapor during cirrus formation experiments in a cloud chamber. We rule out the recent proposed upward modification of αeq, and find values slightly lower than Merlivat and Nief. These experiments also allow us to make a quantitative validation of the kinetic modification expected to occur in supersaturated conditions in the ice–vapor system. In a subset of diffusion-limited experiments, we show that kinetic isotope effects are indeed consistent with published models, including allowing for small surface effects. These results are fundamental for inferring processes on Earth and other planets from water isotopic measurements. They also demonstrate the utility of dynamic in situ experiments for studying fractionation in geochemical systems.

scholarly journals Larval developmental temperature and ambient temperature affect copulation duration in a seed beetle

Behaviour ◽  
2018 ◽  
Vol 155 (1) ◽  
pp. 69-82 ◽  
Author(s):  
R. Vasudeva ◽  
D.C. Deeming ◽  
P.E. Eady
Keyword(s):  
Ambient Temperature ◽  
Callosobruchus Maculatus ◽  
Copulation Duration ◽  
Short Term ◽  
Developmental Temperature ◽  
Effects Of Temperature ◽  
Kinetic Effects ◽  
Development Temperature ◽  
Copulatory Behaviour

Abstract The effects of temperature on cellular, systemic and whole-organism processes can be short-term, acting within seconds or minutes of a temperature change, or long-term, acting across ontogenetic stages to affect an organism’s morphology, physiology and behavioural phenotype. Here we examine the effect of larval development temperature on adult copulatory behaviour in the bruchid beetle, Callosobruchus maculatus. As predicted by temperature’s kinetic effects, copulation duration was longest at the lowest ambient temperature. However, where ambient temperature was fixed and developmental temperature experimentally varied, males reared at the highest temperature were least likely to engage in copulation, whilst those reared at the lowest temperature copulated for longer. Previous research has shown males reared at cooler temperatures inseminate fewer sperm. Thus, in this species longer copulations are associated with reduced sperm transfer. We argue that knowledge of preceding ontogenetic conditions will help to elucidate the causes of variation in copulatory behaviour.

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