scholarly journals Raman Spectroscopy at High Pressures

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Alexander F. Goncharov
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
High Pressures ◽  
Optical Filters ◽  
Planetary Science ◽  
New Materials ◽  
Materials Synthesis ◽  
Scientific Disciplines ◽  
Pressure Metrology ◽  
New Generation

Raman spectroscopy is one of the most informative probes for studies of material properties under extreme conditions of high pressure. The Raman techniques have become more versatile over the last decades as a new generation of optical filters and multichannel detectors become available. Here, recent progress in the Raman techniques for high-pressure research and its applications in numerous scientific disciplines including physics and chemistry of materials under extremes, earth and planetary science, new materials synthesis, and high-pressure metrology will be discussed.

Spectroscopy at High Pressures—Status Report and Update of Instrumental Techniques

1974 ◽  
Vol 28 (6) ◽  
pp. 505-516 ◽  
Author(s):  
John R. Ferraro ◽  
Louis J. Basile
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
High Pressures ◽  
Status Report ◽  
Future Outlook ◽  
Optical Link ◽  
Interferometric Technique ◽  
Pressure Calibration ◽  
Calibration Methods ◽  
Optical Pressure

A status report and update of the instrumentation necessary to obtain spectra of molecules at high pressures are presented. The optical pressure cells used, the spectrophotometer needed to obtain the spectra, the optical link between the two, high pressure spectroscopic windows, pressure calibration methods, and future outlook of the technique will be determined. The use of the high pressure cells with the interferometric technique and for Raman spectroscopy is outlined.

A Study for N2 Coherent Anti-Stokes Raman Spectroscopy Thermometry at High Pressure

1983 ◽  
Vol 37 (6) ◽  
pp. 508-512 ◽  
Author(s):  
Haruhiko Kataoka ◽  
Shiro Maeda ◽  
Chiaki Hirose ◽  
Koichi Kajiyama
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
High Temperature ◽  
Pressure Range ◽  
High Pressures ◽  
Band Width ◽  
Maximum Height ◽  
Temperature Determination ◽  
Engine Cylinder ◽  
Anti Stokes

N2 coherent anti-Stokes Raman spectroscopy (CARS) thermometry over a pressure range 1 to 50 atm has been studied. The CARS profile at high pressure and high temperature was recorded by using the ignition inside a running engine cylinder. The observed Q-branch profile was theoretically fitted by incorporating the collisional narrowing effect, serving for the temperature determination at various pressures. Because of the narrowing effect, the apparent band width showed little change with pressure above 5 atm in general. It has been suggested that the band width at 1/5 of the maximum height can be a useful measure of temperature, while the usual half-width turns out to be hardly practicable at high pressures.

scholarly journals High-pressure, high-temperature molecular doping of nanodiamond

2019 ◽  
Vol 5 (5) ◽  
pp. eaau6073 ◽  
Author(s):  
M. J. Crane ◽  
A. Petrone ◽  
R. A. Beck ◽  
M. B. Lim ◽  
X. Zhou ◽  
...  
Keyword(s):  
High Pressure ◽  
Ion Implantation ◽  
High Pressures ◽  
Noble Gas ◽  
Color Centers ◽  
Vacancy Defects ◽  
High Pressure High Temperature ◽  
Pressure Medium ◽  
Optical Pressure ◽  
Pressure Metrology

The development of color centers in diamond as the basis for emerging quantum technologies has been limited by the need for ion implantation to create the appropriate defects. We present a versatile method to dope diamond without ion implantation by synthesis of a doped amorphous carbon precursor and transformation at high temperatures and high pressures. To explore this bottom-up method for color center generation, we rationally create silicon vacancy defects in nanodiamond and investigate them for optical pressure metrology. In addition, we show that this process can generate noble gas defects within diamond from the typically inactive argon pressure medium, which may explain the hysteresis effects observed in other high-pressure experiments and the presence of noble gases in some meteoritic nanodiamonds. Our results illustrate a general method to produce color centers in diamond and may enable the controlled generation of designer defects.

p-Aminobenzoic acid polymorphs under high pressures

RSC Advances ◽  
2014 ◽  
Vol 4 (30) ◽  
pp. 15534-15541 ◽  
Author(s):  
Tingting Yan ◽  
Kai Wang ◽  
Defang Duan ◽  
Xiao Tan ◽  
Bingbing Liu ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
Diamond Anvil Cell ◽  
High Pressures ◽  
Aminobenzoic Acid ◽  
Aminobenzoic Acids ◽  
Diamond Anvil

The effect of high pressure on two forms (α, β) of p-aminobenzoic acids (PABA) is studied in a diamond anvil cell using in situ Raman spectroscopy.

scholarly journals Phase Transitions in Natural Vanadinite at High Pressures

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1217
Author(s):  
Yingxin Liu ◽  
Liyun Dai ◽  
Xiaojing Lai ◽  
Feng Zhu ◽  
Dongzhou Zhang ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
Structural Changes ◽  
High Pressures ◽  
Color Change ◽  
X Ray Diffraction ◽  
Grüneisen Parameters ◽  
Reversible Phase Transition ◽  
Diamond Anvil ◽  
Gruneisen Parameters

The structural stability of vanadinite, Pb5[VO4]3Cl, is reported by high-pressure experiments using synchrotron radiation X-ray diffraction (XRD) and Raman spectroscopy. XRD experiments were performed up to 44.6 GPa and 700 K using an externally-heated diamond anvil cell (EHDAC), and Raman spectroscopy measurements were performed up to 26.8 GPa at room temperature. XRD experiments revealed a reversible phase transition of vanadinite at 23 GPa and 600 K, which is accompanied by a discontinuous volume reduction and color change of the mineral from transparent to reddish during compression. The high-pressure Raman spectra of vanadinite show apparent changes between 18.0 and 22.8 GPa and finally become amorphous at 26.8 GPa, suggesting structural transitions of this mineral upon compression. The structural changes can be distinguished by the emergence of a new vibrational mode that can be attributed to the distortion of [VO4] and the larger distortion of the V–O bonds, respectively. The [VO4] internal modes in vanadinite give isothermal mode Grüneisen parameters varying from 0.149 to 0.286, yielding an average VO4 internal mode Grüneisen parameters of 0.202.

A novel approach for identifying and synthesizing highdielectric materials

1999 ◽  
Vol 14 (8) ◽  
pp. 3192-3195 ◽  
Author(s):  
J.-H. Park ◽  
J. B. Parise ◽  
P. M. Woodward ◽  
I. Lubomirsky ◽  
O. Stafsudd
Keyword(s):  
High Pressure ◽  
Molar Volume ◽  
High Pressures ◽  
Dielectric Constants ◽  
New Materials ◽  
Twofold Increase ◽  
Novel Approach ◽  
High Pressures And Temperatures ◽  
High Dielectric

Modern telecommunications require materials with high dielectric constants (κ). The number of suitable elements ultimately limits one approach to the discovery of new materials, targeting compositions with high atomic polarizabilities (α). By decreasing the molar volume of compositions with high α, however, we anticipated dramatic increases in κ and demonstrated that this approach works. The quenched high-pressure perovskite polymorph of Na2MTeO6 (M = Ti, Sn) showed a twofold increase in κ, compared to the ilmenite form. This result suggested the highest values of κ occur for compositions with high α, which form quenchable compounds at high pressures and temperatures.

Coexistence of Shallow and Localized Donor Centers in Bulk GaN Crystals Studied by High-Pressure Raman Spectroscopy

1996 ◽  
Vol 449 ◽  
Author(s):  
P. Perlin ◽  
T. Suski ◽  
A. Polian ◽  
J. C. Chervin ◽  
W. Knap ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
High Pressures ◽  
Nitrogen Vacancy ◽  
Donor Center ◽  
Initial Value ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Bulk Gan ◽  
Donor State

ABSTRACTCharacter of the metal-insulator transition which occurs at about 23 GPa in bulk GaN crystals has been studied by means of high pressure Raman spectroscopy. The related freeze-out of electrons is caused by the localized donor state formed by most likely oxygen and emerging at high pressures to the band gap of GaN. As a result, the electron concentration drops from its initial value of 5.1019 cm-3 to about 3. 1018 cm-3. These remaining electrons originate likely from another donor center with effective mass character, probably carbon. The obtained results raise a question whether the nitrogen vacancy is abundant enough to be observed in bulk GaN crystals.

Beyond ultra-high pressure metamorphism: evidence for extremely high pressure conditions during frictional fusion in gigantic landslides using micro-Raman spectroscopy of quartz: the Tsergo Ri (Langtang Himal, Nepal) rockslide

2021 ◽  
Author(s):  
Peter Tropper ◽  
Kurt Krenn ◽  
Diethard Sanders
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
Mass Movement ◽  
Planetary Science ◽  
Raman Mode ◽  
Raman Shift ◽  
Glassy Matrix ◽  
Significant Shift ◽  
Micro Raman Spectroscopy ◽  
Quartz Grains

<p>The Tsergo Ri rockslide represents one of the world's biggest rockslides in crystalline rocks (original volume: 10<sup>10</sup> m<sup>3</sup>). The mass movement comprises migmatites, leucogranites, orthogneisses and paragneisses (Weidinger et al. 2014). During mass-wasting, frictionites and microbreccias formed at the base of the rockslide. The frictionite is mainly composed of a glassy matrix containing biotite, quartz, and abundant plagioclase and K-feldspar. Biotite locally shows a transformation to spinel + glass in highly glassy microdomains. Fe-rich layers in the glass indicate melting of biotite-rich layers of the protolith biotite-bearing orthogneiss. Locally, quartz grains are rimmed by a thin layer of SiO<sub>2</sub> glass (lechatelierite).</p><p>Investigations by McMillan et al. (1991) and Kowitz et al. (2013) have shown that shocked quartz shows a shift in the main A1 Raman mode down to lower wavenumbers with increasing pressures. Tropper et al. (2017) and Sanders et al. (2020) found that quartz from the frictionites in the Köfels landslide (Austria) shows a significant shift of up to 4 cm<sup>-1</sup> in the main A1 Raman mode. Therefore micro-Raman spectroscopy was applied to quartz crystals with and without lechatelierite rims in the Tsergo Ri frictionites. Raman maps of quartz grain areas were prepared using a HORIBA Jobin Yvon LabRam HR800 micro-spectrometer equipped with a 30 mW He-Ne laser (633 nm emission).</p><p>Micro-Raman spectroscopy of 'normal' quartz yielded an intense A1 Raman mode at 464 cm<sup>-1</sup>, whereas<sup>  </sup>quartz without lechatelierite rims shows a shift of this band down to 461.5 cm<sup>-1</sup>. The highest shifts down to 460.5 cm<sup>-1</sup> were observed in quartz grains rimmed by lechatelierite. It is also noteworthy that these grains show an internal gradient of Raman shift of up to 3 cm<sup>-1</sup> from the core (463.5 cm<sup>-1</sup>) to the rim (460.5 cm<sup>-1</sup>) to just below the lechatelierite rims. This is an important observation since lechatelierite formation in frictionites from rockslides was considered so far to be a function of temperature only. Because lechatelierite only rims quartz with strongly shifted A1 band numbers, we interpret lechatelierite formation to be driven by both temperature and pressure, at least under frictionite conditions. The completely molten granitic matrix and the breakdown of biotite to spinel + melt indicates minimum temperatures of 900-1000°C. Sanders et al. (2020) showed that the shifted A1 mode of quartz is stable only below 1100°C, thus giving an upper limit of the temperature range. The observed Raman shift of the A1 mode and the presence of lechatelierite strongly suggest that a pressure of possibly >24-26 GPa was attained (cf. McMillan et al. 1991, Kowitz et al. 2013). The data from Köfels and Tsergo Ri provide the first quantitative estimates of peak pressures during frictionite formation, and show that UHP-modified quartz associated with lechatelierite is common in landslides of silica-rich rocks.</p><p> </p><p> </p><p>References:</p><p>Kowitz et al. 2013: Earth and Planetary Science Letters, 384:17</p><p>McMillan et al. 1992: Physics and Chemistry of Minerals, 19:71</p><p>Sanders et al. 2020: EGU2020-4831</p><p>Tropper et al. 2017: Mitteilungen der Österreichischen Mineralogischen Gesellschaft, 163: 89</p><p>Weidinger et al. 2014: Earth and Planetary Science Letters, 389:62</p>

scholarly journals High-pressure synthesis of materials with new bonding patterns and stoichiometries

2014 ◽  
Vol 70 (a1) ◽  
pp. C750-C750
Author(s):  
Alexander Goncharov
Keyword(s):  
High Pressure ◽  
High Pressures ◽  
Ambient Pressure ◽  
Detailed Knowledge ◽  
New Materials ◽  
Practical Applications ◽  
Theoretical Predictions ◽  
Physical And Chemical ◽  
Synthesis Of Materials ◽  
Bonding Patterns

The search for new materials for advanced technological and practical applications requires breakthroughs in our understanding of how we can control matter most efficiently. Pressure is arguably the most revealing physical variable to delineate various competing physical and chemical phenomena. There are multiple theoretical predictions for existence of novel materials state via changes in the equilibrium chemical bonding at high pressures, but many of these reports do not take into account a possible change in the most stable chemical composition. Also, the implications of this novel extreme chemistry for synthesis of new materials for practical applications remain challenging because high-pressure bonding patterns are often thermodynamically unstable at ambient pressure. Search for a recovery mechanisms or attempts of synthesis in nominally metastable conditions require detailed knowledge of the energy landscape; extensive collaborative efforts of experiment and theory are needed for its determination and for validating the theoretical predictions. I will present new results on synthesis of materials with new bonding patterns and unusual stoichiometries containing hydrogen, nitrogen, carbon, sodium, and halogens. This work has been performed in collaboration with M. Somayazulu, V. V. Struzhkin, V. Prakapenka, E. Stavrou, T. Muramatsu, A. R. Oganov, W. Zhang, Q. Zhu, S. E. Boulfelfel, A. O. Lyakhov, Z. Konopkova, H.-P. Liermann, D.-Y. Kim. I acknowledge the support of DARPA, NSF, EFRee (DOE), Army Research Office, Deep Carbon Observatory, and Carnegie Institution of Washington.

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