A Technique for the Raman Spectroscopy of High Pressure Phases Recovered at Low Temperatures. The Low Frequency Raman Spectrum of Ammonium Fluoride II

1972 ◽  
Vol 43 (6) ◽  
pp. 935-937 ◽  
Author(s):  
P. T. T. Wong ◽  
E. Whalley
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
Raman Spectrum ◽  
Low Temperatures ◽  
Low Frequency ◽  
Ammonium Fluoride

scholarly journals In situ Raman spectroscopy of cubic boron nitride to 90 GPa and 800 K

2014 ◽  
Vol 70 (a1) ◽  
pp. C760-C760
Author(s):  
Shigeaki Ono
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
Raman Spectrum ◽  
Boron Nitride ◽  
Raman Line ◽  
Pressure Dependence ◽  
Diamond Anvil Cell ◽  
Cubic Boron Nitride ◽  
In Situ Raman Spectroscopy ◽  
Diamond Anvil

Cubic boron nitride (c-BN) has some outstanding properties, such as hardness, chemical inertness, high temperature stability, and high thermal conductivity. The Raman spectrum of c-BN exhibits two intense lines at 1054 and 1305 cm-1 under ambient conditions, corresponding to the Brillouin zone center transverse optical (TO) and longitudinal optical (LO) modes, respectively. Previous studies have reported the pressure and temperature dependences of the frequency shift of the modes up to 40 GPa and 2300 K. The Raman line of the LO mode overlaps an intense Raman line of diamond at pressures higher than 3 GPa. Therefore, it is difficult to observe the LO line in high-pressure experiments using the diamond anvil cell. In contrast, previous studies proposed that the TO mode could be used as the pressure calibrant in diamond anvil cells under high pressure and temperature conditions. In this study, we used a diamond anvil cell high-pressure apparatus [1] combined with a Raman spectrometer system to investigate changes in the Raman line of c-BN. The use of a synchrotron radiation source made it possible to determine the precise pressure in the sample chamber. In this study, the temperature and pressure dependences of the Raman spectrum of the TO mode of cubic boron nitride were calibrated for applications to a Raman spectroscopy pressure sensor in optical cells to about 800 K and 90 GPa. A significant deviation from linearity of the pressure dependence is confirmed at pressures above 20 GPa. At ambient temperature, dv/dP slopes are 3.41 and 2.04 cm-1/GPa at 0 and 90 GPa, respectively. The pressure dependence does not significantly change with temperature, as determined from experiments conducted up to 800 K. At pressures above 90 GPa, the Raman spectrum of the TO mode cannot be observed because of an overlap of the signals of cubic boron nitride and diamond used as the anvils in the high-pressure cell.

Raman spectroscopy on single- and multi-walled nanotubes under high pressure

1999 ◽  
Vol 69 (3) ◽  
pp. 309-312 ◽  
Author(s):  
C. Thomsen ◽  
S. Reich ◽  
H. Jantoljak ◽  
I. Loa ◽  
K. Syassen ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure

High-pressure structural phase transition and metallization in Ga2S3 under non-hydrostatic and hydrostatic conditions up to 36.4 GPa

2021 ◽  
Author(s):  
Linfei Yang ◽  
Jianjun Jiang ◽  
Lidong Dai ◽  
Haiying Hu ◽  
Meiling Hong ◽  
...  
Keyword(s):  
Phase Transition ◽  
Raman Spectroscopy ◽  
High Pressure ◽  
Structural Properties ◽  
Structural Phase Transition ◽  
First Principles ◽  
Theoretical Calculations ◽  
Structural Phase

The vibrational, electrical and structural properties of Ga2S3 were explored by Raman spectroscopy, EC measurements, HRTEM and First-principles theoretical calculations under different pressure environments up to 36.4 GPa.

Erratum: Low‐frequency instabilities in the high‐pressure regime of Penning discharges

1979 ◽  
Vol 50 (9) ◽  
pp. 6032-6032
Author(s):  
S. K. Guharay ◽  
S. N. SenGupta ◽  
M. R. Gupta
Keyword(s):  
High Pressure ◽  
Low Frequency ◽  
Pressure Regime

Raman Studies of the Adduct Structure of Cl2 and Br2 with Piaselenole

1980 ◽  
Vol 34 (6) ◽  
pp. 636-638
Author(s):  
J. J. Blaha ◽  
W. Brittain ◽  
C. E. Meloan ◽  
W. G. Fateley
Keyword(s):  
Molecular Structure ◽  
Raman Spectroscopy ◽  
Raman Spectrum ◽  
Long Time

The affinity of 2,1,3-benzoselenadiazole, commonly called piaselenole, for chlorine and bromine molecules has been known for a long time. Raman spectroscopy provides a very interesting method for determining the molecular structure of these 1:1 adducts. The Raman spectrum shows the Cl2 and Br2 molecules in the adduct remain as a dimer molecule.

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