In situ high-pressure study of ammonia borane by Raman and IR spectroscopy

2009 ◽  
Vol 87 (9) ◽  
pp. 1235-1247 ◽  
Author(s):  
Shuntai Xie ◽  
Yang Song ◽  
Zhenxian Liu
Keyword(s):  
High Pressure ◽  
Ir Spectroscopy ◽  
Structural Evolution ◽  
Ammonia Borane ◽  
Ir Absorption ◽  
New Information ◽  
Raman Modes ◽  
Diamond Anvil ◽  
Consistent Information

Pressure-induced structural transformations of the ammonia borane complex (NH3·BH3) were investigated in diamond anvil cells by Raman spectroscopy and synchrotron IR spectroscopy up to 14 GPa at room temperature. Starting with a disordered tetragonal structure, NH3·BH3 is found to undergo several transformations upon compression as monitored by in situ Raman measurements. These transformations are indicated by the sequential changes of characteristic Raman modes as well as by the pressure dependence of these modes. Synchrotron IR absorption spectroscopy provided supplementary and consistent information about the structural evolution of NH3·BH3 under compression. Decompression measurements on NH3·BH3 suggest the pressure-induced transformations are reversible in the entire pressure region. The combined Raman and IR data allowed analysis of possible high-pressure structures of NH3·BH3. Our study significantly complements previous high-pressure Raman studies by providing new information on the structures and stabilities of NH3·BH3.

Behavior of Decomposed Ammonia Borane at High Pressure up to ~10 GPa

2014 ◽  
Vol 783-786 ◽  
pp. 1829-1835
Author(s):  
Yong Zhou Sun ◽  
Jiu Hua Chen ◽  
Vadym Drozd ◽  
Shah Najiba
Keyword(s):  
High Pressure ◽  
Room Temperature ◽  
Diamond Anvil Cell ◽  
Ammonia Borane ◽  
Spectroscopy Study ◽  
High Pressure Phase Transition ◽  
Dihydrogen Bonding ◽  
Diamond Anvil ◽  
Pressure Phase

We conductedin situRaman spectroscopy study on ammonia borane loaded in diamond anvil cell (DAC). The ammonia borane was decomposed at around 140 degree Celsius under the pressure ~0.7 GPa. Raman spectra show the hydrogen was desorbed within 1 hour at 140 degree Celsius. The hydrogen was sealed in the DAC well and cooled down near to room temperature. Applying higher pressure up to ~10 GPa indicates interactions between the products and loss of dihydrogen bonding. No rehydrogenation was detected in the pressure range investigated.Keywords: Ammonia borane; Diamond anvil cell; High pressure; Phase transition

PHASE TRANSITION IN LAYERED PEROVSKITE LIKE MANGANATE Ca3Mn2O7 UNDER HIGH PRESSURE

2001 ◽  
Vol 15 (18) ◽  
pp. 2491-2497 ◽  
Author(s):  
J. L. ZHU ◽  
L. C. CHEN ◽  
R. C. YU ◽  
F. Y. LI ◽  
J. LIU ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Diamond Anvil Cell ◽  
The Other ◽  
Layered Perovskite ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
Diamond Anvil

In situ high pressure energy dispersive X-ray diffraction measurements on layered perovskite-like manganate Ca 3 Mn 2 O 7 under pressures up to 35 GPa have been performed by using diamond anvil cell with synchrotron radiation. The results show that the structure of layered perovskite-like manganate Ca 3 Mn 2 O 7 is unstable under pressure due to the easy compression of NaCl-type blocks. The structure of Ca 3 Mn 2 O 7 underwent two phase transitions under pressures in the range of 0~35 GPa. One was at about 1.3 GPa with the crystal structure changing from tetragonal to orthorhombic. The other was at about 9.5 GPa with the crystal structure changing from orthorhombic back to another tetragonal.

scholarly journals Lab in a DAC – high-pressure crystal chemistry in a diamond-anvil cell

2019 ◽  
Vol 75 (6) ◽  
pp. 918-926 ◽  
Author(s):  
Andrzej Katrusiak
Keyword(s):  
High Pressure ◽  
Diamond Anvil Cell ◽  
Ambient Pressure ◽  
Elevated Pressure ◽  
Sample Volume ◽  
Chemical Research ◽  
New Era ◽  
New Information ◽  
Intermolecular Contacts ◽  
Diamond Anvil

The diamond-anvil cell (DAC) was invented 60 years ago, ushering in a new era for material sciences, extending research into the dimension of pressure. Most structural determinations and chemical research have been conducted at ambient pressure, i.e. the atmospheric pressure on Earth. However, modern experimental techniques are capable of generating pressure and temperature higher than those at the centre of Earth. Such extreme conditions can be used for obtaining unprecedented chemical compounds, but, most importantly, all fundamental phenomena can be viewed and understood from a broader perspective. This knowledge, in turn, is necessary for designing new generations of materials and applications, for example in the pharmaceutical industry or for obtaining super-hard materials. The high-pressure chambers in the DAC are already used for a considerable variety of experiments, such as chemical reactions, crystallizations, measurements of electric, dielectric and magnetic properties, transformations of biological materials as well as experiments on living tissue. Undoubtedly, more applications involving elevated pressure will follow. High-pressure methods become increasingly attractive, because they can reduce the sample volume and compress the intermolecular contacts to values unattainable by other methods, many times stronger than at low temperature. The compressed materials reveal new information about intermolecular interactions and new phases of single- and multi-component compounds can be obtained. At the same time, high-pressure techniques, and particularly those of X-ray diffraction using the DAC, have been considerably improved and many innovative developments implemented. Increasingly more equipment of in-house laboratories, as well as the instrumentation of beamlines at synchrotrons and thermal neutron sources are dedicated to high-pressure research.

scholarly journals Reliability of multigrain indexing for orthorhombic polycrystals above 1 Mbar: application to MgSiO3 post-perovskite

2017 ◽  
Vol 50 (1) ◽  
pp. 120-130 ◽  
Author(s):  
Christopher Langrand ◽  
Nadège Hilairet ◽  
Carole Nisr ◽  
Mathieu Roskosz ◽  
Gábor Ribárik ◽  
...  
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Grain Orientation ◽  
Diamond Anvil Cell ◽  
Polycrystalline Material ◽  
Data Set ◽  
Grain Orientations ◽  
Diamond Anvil ◽  
Diffraction Peaks

This paper describes a methodology for characterizing the orientation and position of grains of an orthorhombic polycrystalline material at high pressure in a diamond anvil cell. The applicability and resolution of the method are validated by simulations and tested on an experimental data set collected on MgSiO3 post-perovskite at 135 GPa. In the simulations, ∼95% of the grains can be indexed successfully with ∼80% of the peaks assigned. The best theoretical average resolutions in grain orientation and position are 0.02° and 1.4 µm, respectively. The indexing of experimental data leads to 159 grains of post-perovskite with 30% of the diffraction peaks assigned with a 0.2–0.4° resolution in grain orientation. The resolution in grain location is not sufficient for in situ analysis of spatial relationships at high pressure. The grain orientations are well resolved and sufficient for following processes such as plastic deformation or phase transformation. The paper also explores the effect of the indexing parameters and of experimental constraints such as rotation range and step on the validity of the results, setting a basis for optimized experiments.

In situ Hall effect measurement on diamond anvil cell under high pressure

2010 ◽  
Vol 81 (11) ◽  
pp. 115101 ◽  
Author(s):  
Tingjing Hu ◽  
Xiaoyan Cui ◽  
Yang Gao ◽  
Yonghao Han ◽  
Cailong Liu ◽  
...  
Keyword(s):  
High Pressure ◽  
Hall Effect ◽  
Diamond Anvil Cell ◽  
Hall Effect Measurement ◽  
Effect Measurement ◽  
Diamond Anvil

High-pressure developments for resonant X-ray scattering experiments at I16

2020 ◽  
Vol 27 (2) ◽  
pp. 351-359
Author(s):  
I. Povedano ◽  
A. Bombardi ◽  
D. G. Porter ◽  
M. Burt ◽  
S. Green ◽  
...  
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
The Body ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Geometry ◽  
Diamond Anvil ◽  
Membrane Cell ◽  
Ray Scattering

An experimental setup to perform high-pressure resonant X-ray scattering (RXS) experiments at low temperature on I16 at Diamond Light Source is presented. The setup consists of a membrane-driven diamond anvil cell, a panoramic dome and an optical system that allows pressure to be measured in situ using the ruby fluorescence method. The membrane cell, inspired by the Merrill–Bassett design, presents an asymmetric layout in order to operate in a back-scattering geometry, with a panoramic aperture of 100° in the top and a bottom half dedicated to the regulation and measurement of pressure. It is specially designed to be mounted on the cold finger of a 4 K closed-cycle cryostat and actuated at low-temperature by pumping helium into the gas membrane. The main parts of the body are machined from a CuBe alloy (BERYLCO 25) and, when assembled, it presents an approximate height of 20–21 mm and fits into a 57 mm diameter. This system allows different materials to be probed using RXS in a range of temperatures between 30 and 300 K and has been tested up to 20 GPa using anvils with a culet diameter of 500 µm under quasi-cryogenic conditions. Detailed descriptions of different parts of the setup, operation and the developed methodology are provided here, along with some preliminary experimental results.

scholarly journals Experimental method for in situ determination of material textures at simultaneous high pressure and high temperature by means of radial diffraction in the diamond anvil cell

2009 ◽  
Vol 80 (10) ◽  
pp. 104501 ◽  
Author(s):  
Hanns-Peter Liermann ◽  
Sébastien Merkel ◽  
Lowell Miyagi ◽  
Hans-Rudolf Wenk ◽  
Guoyin Shen ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Experimental Method ◽  
Diamond Anvil Cell ◽  
Diamond Anvil

Growth and High Pressure Investigation of (C60)n@SWNT

2012 ◽  
Vol 442 ◽  
pp. 26-30
Author(s):  
Yong Gang Zou ◽  
Xiao Hui Ma ◽  
Quan Lin Shi ◽  
Guo Jun Liu ◽  
Qing Xue Sui ◽  
...  
Keyword(s):  
High Pressure ◽  
Laser Irradiation ◽  
Diamond Anvil Cell ◽  
Pressure Effects ◽  
Diffusion Method ◽  
Uv Laser ◽  
One Dimensional ◽  
Diamond Anvil ◽  
830 Nm Laser

The (C60)n@SWNT (peapod) samples were prepared by vapor diffusion method. We performed the high pressure Raman measurements on the peapod samples by using a Mao-Bell type diamond anvil cell (DAC). In the In situ high pressure experiments, the peapod samples were exposed under UV laser line irradiation. The polymerization of C60 molecules in SWNT cave under both laser irradiation and pressure effects has been studied. The Raman spectra of the released samples from high pressure indicated that C60s form one-dimensional orthorhombic polymer. For the Raman measurements, two different excitation wavelengths were used, 325 nm laser and 830 nm laser.

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