Absorption coefficients of overtone and combination modes of quartz

Shinoda, Keiji; Aikawa, Nobuyuki

doi:10.1180/minmag.1994.058.393.08

Cited by 8 publications

(8 citation statements)

References 13 publications

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“…The intensity of the extra mode (Fig. 3, Table 2) increases with pressure whilst the strong mode at 3696 cm −1 weakens (Kruger, Williams & Jeanloz 1989; Shinoda & Aikawa 1998). The results at elevated pressure pertain to astronomical environments, as decreasing temperature similarly contracts the lattice.…”

Section: Infrared Spectroscopic Resultsmentioning

confidence: 99%

“…In the middle section are edge‐on schematic views of the three types of tightly bonded layers found in hydrous minerals. (d) Atomic arrangement in the unit cell of brucite emphasizing the placement of the H atoms (after Shinoda & Aikawa 1998). The thin arrow shows the bending motion of H + tilted from the c ‐axis (thick arrow) of the crystalline lattice.…”

Section: Connection Of Infrared Spectral Patterns With Mineral Strumentioning

confidence: 99%

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Quantitative Infrared Spectra of Hydrosilicates and Related Minerals

Hofmeister

Bowey

2006

Monthly Notices of the Royal Astronomical Society

101

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Absorption coefficients associated with atomic motions of species expected in astronomical environments are determined from infrared measurements of various hydrosilicates, hydrated magnesium oxide, and the Al‐bearing chain silicate, sapphirine. Band types measured include O–H stretching modes near 3 μm, Si–O stretching motions near 10 μm, Si–O–Si bends near 14 μm, O–Si–O bends near 20 μm, and translations of cations such as Mg and Ca near 50–200 μm. We obtain data from films of varying thickness and use a ratioing method. First, bandstrengths of O–H fundamentals were determined from spectra obtained from films of controlled thicknesses, generally 6 μm. The O–H absorbance strength was then used to accurately determine thickness for a thinner film of each mineral (found to be <1 μm), thus providing bandstrengths of all other absorptions. Thin films were prepared such that the fundamental lattice modes showed intrinsic behaviour (i.e. band shapes were unchanged upon further thinning) and O–H modes are well resolved above the spectral noise. Bandstrengths were found to depend weakly on structure and should be applicable to other silicate minerals, allowing estimation of elemental concentrations independent of knowing the speciation of dust in astronomical environments. Comparison with observational data of NGC 6302 suggests that lizardite and saponite could be present in addition to refractory minerals.

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Section: Infrared Spectroscopic Resultsmentioning

confidence: 99%

Section: Connection Of Infrared Spectral Patterns With Mineral Strumentioning

confidence: 99%

Quantitative Infrared Spectra of Hydrosilicates and Related Minerals

Hofmeister

Bowey

2006

Monthly Notices of the Royal Astronomical Society

101

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“…Analysis of darker grains with laser Raman acquired spectra with an intense peak at c. 150cm-', attributed to the 0-Ti-0 symmetrical bend (Frost, 1997), with additional low intensity bands at 197, 400, Significant bands are evident in the regions around a700cm ' (Si-0-Si, Si-0--A1 and Ti-0 molecular vibrations) and 800-1000 cm-', representative of silicate and aluminosilicate minerals with Si-0 and Si-&A1 stretches. Overtone absorptions from quartz (Shimoda & Aikawa 1994) are identified at 1796, 1883 and 1991 cm '. Absorptions in the regions 1500-1600 and 2800-3000cm-' arise from the vibration of organic materials in the test wall.…”

Section: Raman Spectroscopymentioning

confidence: 98%

Marginal marine agglutinated foraminifera: affinities for mineral phases

Allen

Roberts

Murray

1999

J. Micropalaeontol.

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Abstract. The major agglutinated constituents in test material of marginal marine foraminifera are identified as α-quartz and clay particles using complementary spectroscopic techniques. Electron dispersive scattering analysis, micro-laser Raman and Fourier transform infrared (FTIR) spectroscopic techniques revealed detail about elemental and mineral polymorph constituents in test walls. Additionally, FTIR identifies the existence of organic cements and lining materials in wall structures. Micro-laser Raman specifically characterized the titanium oxide mineral, anatase, as a distinctive fraction of agglutinate in Ammobaculites balkwilli Haynes. The mineral represents ≈10% of the test material, but comprises a minor component of the sediment and is identified in sediments only after heavy mineral separation. The enhanced concentration of anatase in the test of A. balkwilli suggests that there is a preferential selection for anatase. This provides further evidence that certain foraminifera can select grains specifically, which implies that there exists a selective mechanism and interaction between the organic (secreted) phases in the test walls and inorganic (grain surface) materials.

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“…Following previous studies [52], these peaks are seen in slow-scan modes of FTIR-PAS and almost disappear in rapid-scan IMF modes at 7.5 kHz or higher. The peak shapes make it possible to exclude the contributions from vibrations of amorphous SiO 2 and quartz species [104][105][106]. Methyl group vibrations at 2880 cm −1 and 2970 cm −1 are absent in ATR-FTIR, weak in DRIFT, and distinct in FTIR-PAS.…”

Section: Ch Region (3100-2800 CM −1 )mentioning

confidence: 99%

Organic Matter and Mineral Composition of Silicate Soils: FTIR Comparison Study by Photoacoustic, Diffuse Reflectance, and Attenuated Total Reflection Modalities

2021

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This study aims to compare photoacoustic (FTIR–PAS), diffuse reflectance (DRIFT), and attenuated total reflection (ATR) FTIR modalities in the wide wavenumber range from NIR (7500 cm−1) to FIR (150 cm−1) for the same silicate soil samples under the same conditions. The possibilities of non-destructive rapid qualitative analysis of soils by these modalities without comprehensive data treatment were compared. The assignment of more than 100 bands for the chernozem and sod-podzolic as common types of silicate types of soil was made. The following groups of bands of organic matter and inorganic matrix were reliably found in spectra of all or at least two modalities: 3690–3680 cm−1 (hydrogen-bonded SiO–H…H2O stretch, not ATR), 2930–2910 cm−1 and 2860–2850 cm−1 (methylene stretch), 1390–1380 cm−1, (symmetric stretch carboxylate, DRIFT and FTIR–PAS); 2000–1990 cm−1, 1885 cm−1, and 1790–1783 cm−1 (SiO2 overtones, DRIFT and FTIR–PAS), 1163–1153 cm−1, SiO2 lattice (not FTIR–PAS), 1037 cm−1 (Si–O or Al–O stretch), 796 cm−1 (lattice symmetrical Si–O–Si stretch); 697 cm−1, SiO2; and 256 cm−1 (not FTIR–PAS). Amide I, II, and III bands appear in DRIFT and FTIR–PAS spectra while not in ATR. Except for methylene and carboxylate groups, CH vibrations (3100–2900 cm−1) are not seen in ATR. Bands at 1640–1630 cm−1, 1620–1610 cm−1, 1600–1598 cm−1 (primary water bands and probably carboxylate) appear in the spectra of all three modalities but are unresolved and require data treatment. It is preferable to use all three modalities to characterize both soil organic matter and mineral composition. DRIFT provides the maximum number of bands in all three modalities and should be selected as a primary technique in the NIR and 4000–2000 cm−1 regions for hydrogen-bonding bands, CHX groups, and the silicate matrix. ATR–FTIR complements DRIFT and provides a good sensitivity for soil water and the matrix in 2000–400 cm−1. FTIR–PAS in 4000–1500 cm−1 reveals more bands than DRIFT and shows the highest sensitivity for absorption bands that do not appear in DRIFT or ATR-IR spectra. Thus, FTIR–PAS is expedient for supporting either DRIFT or ATR–FTIR. This modality comparison can be a basis for methodological support of IR spectroscopy of soils and similar organomineral complexes.

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Absorption coefficients of overtone and combination modes of quartz

Cited by 8 publications

References 13 publications

Quantitative Infrared Spectra of Hydrosilicates and Related Minerals

Quantitative Infrared Spectra of Hydrosilicates and Related Minerals

Marginal marine agglutinated foraminifera: affinities for mineral phases

Organic Matter and Mineral Composition of Silicate Soils: FTIR Comparison Study by Photoacoustic, Diffuse Reflectance, and Attenuated Total Reflection Modalities

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