Is cerussite an aragonite? Longitudinal optical–transverse optical splitting in the single-crystal Raman spectra

1985 ◽  
pp. 916-917 ◽  
Author(s):  
Ray Durman ◽  
Upali A. Jayasooriya ◽  
Sidney F. A. Kettle
Keyword(s):  
Single Crystal ◽  
Raman Spectra ◽  
Longitudinal Optical ◽  
Transverse Optical

Polarized Raman spectra of an oriented single crystal of barium nitrite monohydrate

1983 ◽  
Vol 61 (3) ◽  
pp. 608-612 ◽  
Author(s):  
O. P. Lamba ◽  
H. D. Bist ◽  
Y. S. Jain
Keyword(s):  
Single Crystal ◽  
Raman Spectra ◽  
Longitudinal Optical ◽  
Transverse Optical ◽  
Polarized Raman ◽  
First Time ◽  
Barium Nitrite ◽  
Lattice Modes ◽  
Oriented Single Crystal

The symmetries of the observed Raman lines in the 4000–30 cm−1 region in different orientations of a single crystal of Ba(NO2)2•H2O have been determined and the spectra have been analysed in terms of the phonons originating from the internal modes of the NO2− and H2O groups and the external lattice modes. The longitudinal-optical and transverse-optical (LO–TO) splittings arising from the Coulomb forces in the crystal arc reported for the first time.

Nondestructive Characterizations of Au-Catalyzed GaAs Nanowires on GaAs(111)B Substrates via Identifications of 1st Order Optical Phonon Modes Using μ-Raman Spectroscopy

2020 ◽  
Vol 20 (7) ◽  
pp. 4358-4363
Author(s):  
Jeung Hun Park ◽  
Richard S. Kim ◽  
Se-Jeong Park ◽  
Gye-Choon Park ◽  
Choong-Heui Chung
Keyword(s):  
Raman Spectroscopy ◽  
Dose Rate ◽  
Raman Spectra ◽  
Optical Phonon ◽  
Longitudinal Optical ◽  
Transverse Optical ◽  
Longitudinal Optical Phonon ◽  
Phonon Modes ◽  
Gaas Nanowires ◽  
Beam Dose

We report the relation between the catalyst patterning conditions and the intensity of the 1st order Raman active modes in Au-catalyzed GaAs nanowire bundles. We fabricated e-beam lithographically Au-patterned GaAs(111)B substrates by varying the patterning conditions (e-beam dose rate, dot-size and interdot-spacings), and grew GaAs nanowires via vapor–liquid–solid process using a solid-source molecular beam epitaxy. To understand the effects of the substrate preparation conditions and resulting morphologies on the optical characteristics of 1st order transverse optical and longitudinal optical phonon modes of GaAs, we characterized the nanowire bundles using complementary μ-Raman spectroscopy and scanning electron microscopy as a function of the e-beam dose rate (145–595 μC/cm2), inter-dot spacing (100 and 150 nm) and pattern size (100 and 150 nm). Ensembles of single crystalline GaAs nanowires covered with different Au-thickness exhibit a downshift and asymmetric broadening of the 1st order transverse optical and longitudinal optical phonon peaks relative to GaAs bulk modes. We also showed that the sensitivity of a downshift and broadening of Raman spectra are directly related to morphological and surface coverage variations in as-grown nanowires. We observed clear increases of the transverse optical and longitudinal optical intensity as well as the relatively higher peak shift and broadening of Raman spectra from the 100 nm patterning in response to the dose rate change. Strong dependence of Raman spectra of the nanowire bundles on the e-beam dose rate changes are attributed to the variations in spatial density, size, shape and random growth orientation of the wires. We have shown that the identification of the changes in GaAs longitudinal optical and Arsenic anti-site peaks is good indicators to characterize the quality of as-grown GaAs nanowires. Our finding confirms the utilization of Raman spectroscopy as a powerful tool for characterizing chemical, structural, and morphological information of as-grown nanowires within the supporting substrate.

Single Crystal Raman Spectra of the Phase Transition in KTCNQ

1982 ◽  
Vol 85 (1) ◽  
pp. 297-303 ◽  
Author(s):  
A. D. Bandrauk ◽  
K. D. Truong ◽  
S. Jandl
Keyword(s):  
Phase Transition ◽  
Single Crystal ◽  
Raman Spectra

Growth of Yb:Y2O3 single crystals by the micro-pulling-down method

2004 ◽  
Vol 848 ◽  
Author(s):  
A. Novoselov ◽  
J. H. Mun ◽  
A. Yoshikawa ◽  
G. Boulon ◽  
T. Fukuda
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Raman Spectra ◽  
Lattice Constant ◽  
Decay Time ◽  
Dopant Distribution ◽  
High Homogeneity ◽  
Linear Decrease ◽  
Crystal Laser

ABSTRACT(Ybx Y1-x)2O3 (x = 0.0, 0.005, 0.05, 0.08 and 0.15) promising single crystal laser rods of 4.2 mm in diameter and 15–20 mm in length have been grown from the rhenium crucible by the micro-pulling-down method in Ar + H2(3–4%) atmosphere. Linear decrease of lattice constant with the increase of Yb3+-content was observed. High homogeneity of the Yb3+-dopant distribution has been demonstrated. Absorption, emission and Raman spectra have been recorded and decay time was approximated.

scholarly journals THE POLARIZED RAMAN SPECTRA FOR SINGLE CRYSTAL LiB3O5

1996 ◽  
Vol 45 (5) ◽  
pp. 885
Author(s):  
JANG YI-JIAN ◽  
WANG YUE ◽  
ZENG LING-ZHI ◽  
LIU YU-LONG
Keyword(s):  
Single Crystal ◽  
Raman Spectra ◽  
Polarized Raman

Crystal chemistry of lamprophyllite-group minerals from the Murun alkaline complex (Russia) and pegmatites of Rocky Boy and Gordon Butte (USA): single crystal X-ray diffraction and Raman spectroscopy study

2021 ◽  
Vol 77 (2) ◽  
Author(s):  
Sergey M. Aksenov ◽  
Anastasia D. Ryanskaya ◽  
Yuliya V. Shchapova ◽  
Nikita V. Chukanov ◽  
Nikolay V. Vladykin ◽  
...  
Keyword(s):  
Solid Solution ◽  
Single Crystal ◽  
Raman Spectra ◽  
Crystal Chemistry ◽  
Solid Solution Series ◽  
X Ray Diffraction ◽  
Alkaline Complex ◽  
Oh Groups ◽  
X Ray ◽  
Solution Series

Specific features of the crystal chemistry of lamprophyllite-group minerals (LGMs) are discussed using the available literature data and the results of the single-crystal X-ray diffraction and a Raman spectroscopic studies of several samples taken from the Murun alkaline complex (Russia), and Rocky Boy and Gordon Butte pegmatites (USA) presented here. The studied samples are unique in their chemical features and the distribution of cations over structural sites. In particular, the sample from the Gordon Butte pegmatite is a member of the barytolamprophyllite–emmerichite solid solution series, whereas the samples from the Murun alkaline complex and from the Rocky Boy pegmatite are intermediate members of the solid solution series formed by lamprophyllite and a hypothetical Sr analogue of emmerichite. The predominance of O2− over OH− and F− at the X site is a specific feature of sample Cha-192 from the Murun alkaline complex. New data on the Raman spectra of LGMs obtained in this work show that the wavenumbers of the O—H stretching vibrations depend on the occupancies of the M2 and M3 sites coordinating with (OH)− groups. Cations other than Na+ and Ti4+ (mainly, Mg and Fe3+) can play a significant role in the coordination of the X site occupied by (OH)−. Data on polarized Raman spectra of an oriented sample indicate that the OH groups having different local coordinations have similar orientations with respect to the crystal. The calculated measures of similarity (Δ) for lamprophyllite and ericssonite are identical (0.157 and 0.077 for the 2M- and 2O-polytypes, respectively), which indicates that these minerals are crystal-chemically isotypic and probably should be considered within the same mineral group by analogy to the other mineralogical groups which combine isotypic minerals.

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