Crystal structures and high-temperature vibrational spectra for synthetic boron and aluminum doped hydrous coesite

2020 ◽  
Author(s):  
Yu Ye ◽  
Yunfan Miao ◽  
Joseph R. Smyth ◽  
Junfeng Zhang
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Single Crystals ◽  
Vibrational Spectra ◽  
Fourier Transformation ◽  
Ambient Pressure ◽  
Al Content ◽  
Al Substitution ◽  
Long Time

<p>Coesite, a high-pressure SiO2 polymorph, has drawn extensive interest from the mineralogical community for a long time. In this study, we synthesized hydrous coesite samples with different B and Al concentrations at 5 and 7.5 GPa (1273 K). The B concentration could be more than 400 B/10<sup>6</sup>Si with about 300 ppmw. H2O, while the Al content can be as much as 1200 ~ 1300 Al/10<sup>6</sup>Si with CH2O restrained to be less than 10 ppmw. Hence, B-substitution may prefer the mechanism of Si<sup>4+</sup> = B<sup>3+</sup> + H<sup>+</sup>, whereas Al-substitution could be dominated by 2Si<sup>4+</sup> = 2Al<sup>3+</sup> + O<sub>V</sub>. The doped B<sup>3+</sup> and Al<sup>3+</sup> cations may be concentrated in the Si1 and Si2 tetrahedra, respectively, and make noticeable changes in the Si-O4 and Si-O5 bond lengths. In-situ high-temperature Raman and Fourier Transformation Infrared (FTIR) spectra were collected at ambient pressure. The single crystals of coesite were observed to be stable up to 1500 K. The isobaric Grüneisen parameters (ϒ<sub>i<em>P</em></sub>) of the external modes (< 350 cm<sup>-1</sup>) are systematically smaller in the Al-doped samples, as compared with those for the Al-free ones, while most of the OH-stretching bands shift to higher frequencies in the high temperature range up to ~ 1100 K</p>

scholarly journals Crystal Structures and High-Temperature Vibrational Spectra for Synthetic Boron and Aluminum Doped Hydrous Coesite

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 642 ◽  
Author(s):  
Yunfan Miao ◽  
Youwei Pang ◽  
Yu Ye ◽  
Joseph R. Smyth ◽  
Junfeng Zhang ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Single Crystals ◽  
Vibrational Spectra ◽  
Fourier Transformation ◽  
Ambient Pressure ◽  
Al Content ◽  
Al Substitution ◽  
Long Time

Coesite, a high-pressure SiO2 polymorph, has drawn extensive interest from the mineralogical community for a long time. In this study, we synthesized hydrous coesite samples with different B and Al concentrations at 5 and 7.5 GPa (1273 K). The B concentration could be more than 400 B/106Si with about 300 ppmw H2O, while the Al content can be as much as 1200 to 1300 Al/106Si with CH2O restrained to be less than 10 ppmw. Hence, B-substitution may prefer the mechanism of Si4+ = B3+ + H+, whereas Al-substitution could be dominated by 2Si4+ = 2Al3+ + OV. The doped B3+ and Al3+ cations may be concentrated in the Si1 and Si2 tetrahedra, respectively, and make noticeable changes in the Si–O4 and Si–O5 bond lengths. In-situ high-temperature Raman and Fourier Transformation Infrared (FTIR) spectra were collected at ambient pressure. The single crystals of coesite were observed to be stable up to 1500 K. The isobaric Grüneisen parameters (γiP) of the external modes (<350 cm−1) are systematically smaller in the Al-doped samples, as compared with those for the Al-free ones, while most of the OH-stretching bands shift to higher frequencies in the high temperature range up to ~1100 K

High-Pressure Synthesis, Crystal Structure, and Properties of the New Orthorhombic Rare-Earth meta-Oxoborates RE(BO2)3 (RE = Dy – Lu)

2004 ◽  
Vol 59 (2) ◽  
pp. 202-215 ◽  
Author(s):  
Holger Emme ◽  
Tanja Nikelski ◽  
Thomas Schleid ◽  
Rainer Pöttgen ◽  
Manfred Heinrich Möller ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Ambient Pressure ◽  
Structure And Properties ◽  
Crystal Data ◽  
Temperature Conditions ◽  
Pressure Synthesis ◽  
Ir Spectroscopic ◽  
Pressure Phase

The new orthorhombic meta-oxoborates RE(BO2)3 (≡REB3O6) (RE = Dy-Lu) have been synthesized under high-pressure and high-temperature conditions in a Walker-type multianvil apparatus at 7.5 GPa and 1100 °C. They are isotypic to the known ambient pressure phase Tb(BO2)3, space group Pnma. In contrast to Dy(BO2)3, which was also obtained in small amounts under high-temperature conditions, the preparation of the higher orthorhombic homologues RE(BO2)3 (RE = Ho-Lu) was only possible using high-pressure. The meta-oxoborates RE(BO2)3 (RE = Dy-Er) were synthesized as pure products, whereas the orthorhombic phases with RE = Tm-Lu were only obtained as byproducts. With the exception of Yb(BO2)3 it was possible to establish single crystal data for all compounds. The results of temperature-resolved in-situ powder-diffraction measurements, DTA, IR-spectroscopic investigations, and magnetic properties are also presented.

scholarly journals Single-pass flow-through reaction cell for high-temperature and high-pressurein situneutron diffraction studies of hydrothermal crystallization processes

2012 ◽  
Vol 45 (2) ◽  
pp. 166-173 ◽  
Author(s):  
Fang Xia ◽  
Joël Brugger ◽  
Gujie Qian ◽  
Yung Ngothai ◽  
Brian O'Neill ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Flow Rate ◽  
Room Temperature ◽  
Ambient Pressure ◽  
Vacuum Furnace ◽  
Hydrothermal Crystallization ◽  
Single Pass ◽  
Flow Through

A large-volume single-pass flow-through cell forin situneutron diffraction investigation of hydrothermal crystallization processes is reported. The cell is much more versatile than previous designs owing to the ability to control independently and precisely temperature (up to 673 K), pressure (up to 46 MPa), flow rate (0.01–10 ml min−1) and reaction-fluid volume (≥65 ml). Such versatility is realized by an innovative design consisting of a room-temperature and ambient-pressure external fluid supply module, a high-pressure reaction module which includes a high-temperature sample compartment enclosed in a vacuum furnace, and a room-temperature and high-pressure backpressure regulation module for pressure control. The cell provides a new avenue for studying various parameters of hydrothermal crystallizations independently,in situand in real time at extreme hydrothermal conditions (e.g.supercritical). The cell was successfully commissioned on the high-intensity powder diffractometer beamline, Wombat, at the Australian Nuclear Science and Technology Organisation by investigating the effect of pressure on the hydrothermal pseudomorphic conversion from SrSO4(celestine) to SrCO3(strontianite) at a constant temperature of 473 K and flow rate of 5 ml min−1. The results show that the increase of pressure exerts a nonlinear effect on the conversion rate, which first increases with increasing pressure from 14 to 20 MPa, and then decreases when pressure further increases to 24 MPa.

scholarly journals High-pressure and environment effects in selenourea and its labile crystal field around molecules

2021 ◽  
Vol 77 (3) ◽  
pp. 449-455
Author(s):  
Kinga Roszak ◽  
Andrzej Katrusiak
Keyword(s):  
High Pressure ◽  
Single Crystals ◽  
Ambient Pressure ◽  
Recrystallization Process ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Environment Effects ◽  
Diamond Anvil ◽  
Trigonal Phase

Ambient-pressure trigonal phase α of selenourea SeC(NH2)2 is noncentrosymmetric, with high Z′ = 9. Under high pressure it undergoes several intriguing transformations, depending on the pressure-transmitting medium and the compression or recrystallization process. In glycerine or oil, α-SeC(NH2)2 transforms into phase β at 0.21 GPa; however in water, phase α initially increases its volume and can be compressed to 0.30 GPa due to the formation of α-SeC(NH2)2·xH2O. The single crystals of α-SeC(NH2)2 and of its partial hydrate α-SeC(NH2)2·xH2O are shattered by pressure-induced transitions. Single crystals of phase β-SeC(NH2)2 were in situ grown in a diamond-anvil cell and studied by X-ray diffraction. The monoclinic phase β is centrosymmetric, with Z′ = 2. It is stable to 3.20 GPa at least, but it cannot be recovered at ambient conditions due to strongly strained NH...Se hydrogen bonds. No hydrogen-bonding motifs present in the urea structures have been found in selenourea phases α and β.

In Situ High-Pressure and High-Temperature Experiments onn-Heptane

2012 ◽  
Vol 66 (2) ◽  
pp. 233-236 ◽  
Author(s):  
Erwei Qiao ◽  
Haifei Zheng ◽  
Changxing Long
Keyword(s):  
High Pressure ◽  
High Temperature

Evolution of Disordering in SiC under High Pressure High Temperature Conditions: In-situ Powder Diffraction Study

1998 ◽  
Vol 278-281 ◽  
pp. 612-617 ◽  
Author(s):  
Bogdan F. Palosz ◽  
Svetlana Stelmakh ◽  
Stanislaw Gierlotka ◽  
M. Aloszyna ◽  
Roman Pielaszek ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Diffraction Study ◽  
Powder Diffraction ◽  
Temperature Conditions ◽  
High Pressure High Temperature

Synthesize Ti3SiC2 and Ti3SiC2-Diamond Composites at High Pressure and High Temperature

2012 ◽  
Vol 512-515 ◽  
pp. 671-675 ◽  
Author(s):  
Ai Guo Zhou ◽  
Liang Li ◽  
Tai Chao Su ◽  
Shang Sheng Li
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Intermediate Products ◽  
Diamond Particles ◽  
Ternary Carbide ◽  
The Matrix

Ti3SiC2, a ternary carbide, was proposed at this paper to use as the binder of polycrystalline diamonds to overcome the weaknesses of traditional metal binders and ceramic binders. Ti3SiC2was first reported to be in-situ synthesized under high pressure (4GPa) and at high temperature (1400°C) (HPHT) from the mixtures of Ti, Si and graphite powders or the mixture of Ti, SiC and graphite powders. Ti3SiC2-damond composites were also made at HPHT from the previous mixtures and diamond particles. TiCx, Ti5Si3Cxand TiSi2were main impurities and/or intermediate products of Ti3SiC2samples synthesized at HPHT. Ti3SiC2content increased as synthesized time increased from 10 min to 60 min. For as-synthesized composites, diamond particles were evenly distributed in matrix. The diamond particles are bonded well with the matrix by three types of interface.

scholarly journals Sealed rotors for in situ high temperature high pressure MAS NMR

2015 ◽  
Vol 51 (70) ◽  
pp. 13458-13461 ◽  
Author(s):  
Jian Zhi Hu ◽  
Mary Y. Hu ◽  
Zhenchao Zhao ◽  
Suochang Xu ◽  
Aleksei Vjunov ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Mas Nmr ◽  
Material Synthesis ◽  
Widespread Application ◽  
High Temperature High Pressure

Perfectly sealed rotors were designed for the widespread application of in situ MAS NMR in catalysis, material synthesis, metabolomics, and more.

Application and Exploration of Early In-Situ Combustion Huff-and-Puff Technology in a Deep Undisturbed Reservoir with Extra Heavy Oil

2021 ◽  
pp. 1-13
Author(s):  
Wang Xiaoyan ◽  
Zhao Jian ◽  
Yin Qingguo ◽  
Cao Bao ◽  
Zhang Yang ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Heavy Oil ◽  
Gas Injection ◽  
Thermal Recovery ◽  
Oil Field ◽  
Pilot Test ◽  
In Situ Combustion ◽  
Coiled Tubing

Summary Achieving effective results using conventional thermal recovery technology is challenging in the deep undisturbed reservoir with extra-heavy oil in the LKQ oil field. Therefore, in this study, a novel approach based on in-situ combustion huff-and-puff technology is proposed. Through physical and numerical simulations of the reservoir, the oil recovery mechanism and key injection and production parameters of early-stage ultraheavy oil were investigated, and a series of key engineering supporting technologies were developed that were confirmed to be feasible via a pilot test. The results revealed that the ultraheavy oil in the LKQ oil field could achieve oxidation combustion under a high ignition temperature of greater than 450°C, where in-situ cracking and upgrading could occur, leading to greatly decreased viscosity of ultraheavy oil and significantly improved mobility. Moreover, it could achieve higher extra-heavy-oil production combined with the energy supplement of flue gas injection. The reasonable cycles of in-situ combustion huff and puff were five cycles, with the first cycle of gas injection of 300 000 m3 and the gas injection volume per cycle increasing in turn. It was predicted that the incremental oil production of a single well would be 500 t in one cycle. In addition, the supporting technologies were developed, such as a coiled-tubing electric ignition system, an integrated temperature and pressure monitoring system in coiled tubing, anticorrosion cementing and completion technology with high-temperature and high-pressure thermal recovery, and anticorrosion injection-production integrated lifting technology. The proposed method was applied to a pilot test in the YS3 well in the LKQ oil field. The high-pressure ignition was achieved in the 2200-m-deep well using the coiled-tubing electric igniter. The maximum temperature tolerance of the integrated monitoring system in coiled tubing reached up to 1200°C, which provided the functions of distributed temperature and multipoint pressure measurement in the entire wellbore. The combination of 13Cr-P110 casing and titanium alloy tubing effectively reduced the high-temperature and high-pressure oxygen corrosion of the wellbore. The successful field test of the comprehensive supporting engineering technologies presents a new approach for effective production in deep extra-heavy-oil reservoirs.

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