SPAFMSR



Buzgar N., Apopei A. I., Buzatu A. (2009) - Romanian Database of Raman Spectroscopy (http://rdrs.uaic.ro)
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Formula: |
BaCO3 |
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Crystal Data: |
Crystal System: Orthorhombic - Dipyramidal |
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Point Group: 2m/2m/2m |
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Cell Data: |
Space Group: Pmcn, a = 5.313, b = 8.904, c = 6.43, Z = 4 |
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Density (calc.) = 4.31 and V = 304.18 Å3 |
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Element color: Ba, C, O |
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Sample no. 5484 from the "Mineralogy and Petrography Museum Grigore Cobălcescu" of "Alexandru Ioan Cuza" University, Iaşi. Origin: Alston - England. Click image to enlarge |
The characteristic Raman band due to the external vibration mode (M-CO3) at 227 cm-1 and 222 cm-1, 285 cm-1 for witherite and synthetic BaCO3, respectively, and the ν1 internal mode (symmetric stretching) for both witherite sample at 1059 cm-1 are easily distinguished. In the Raman spectrum of the witherite and synthetic BaCO3 samples don't have values below 200 cm-1 because the spectral range is between 200-3400 cm-1.
The Raman spectra for the witherite and synthetic BaCO3 are very similar the only differences are found in the 200-300 cm-1 region. In the synthetic BaCO3 spectra appear one peak in addition at 285 cm-1 attributed to the external vibration mode. As can be seen in Raman spectra, witherite and BaCO3 synthetic do not present values below 200 cm-1 because the spectral range is between 200-3400 cm-1. The intense ν1 symmetric stretching mode of carbonate group is at 1059 cm-1 for both spectra. The bands at 1422 cm-1 and 1421 cm-1 are due to the ν3 asymmetric stretching mode, and the bands at 1511 cm-1 and 1508 cm-1 are not assigned. The ν2 vibration mode is not observed. The Raman line at 693 cm-1 is attributed to ν4 vibration.
Buzgar et al., 20091 | Buzgar et al., 20091 | Krishnamurti, 1960 | Beny, 1989 | Assignment |
sample no. 5484 | synthetic BaCO3 | |||
227 | 222, 285 | 227 | 224 | T(M,CO3) |
693 | 693 | 691 699 |
690 696 |
v4 - symmetric deformation |
NO | NO | 852* | v2 - asymmetric deformation | |
1059 | 1059 | 1061 | 1035 1059 |
v1 - symmetric stretch |
1422 1511 |
1421 1508 |
1394 1409 1421 |
1419 1505 |
v3 - asymmetric stretching |
NO | NO | 2116* | 2v1 |
• The Mineralogy Database [link]
• Crystal data (.cif file) from the American Mineralogist Crystal Structure Database [link]
• 1BUZGAR N., APOPEI A. I. (2009) - The Raman study on certain carbonates. Analele Stiintifice ale Universitatii “Al. I. Cuza” - Iasi, Tome 55, issue 2, 97-112 [link]
• KRISHNAMURTI D. (1960) - The Raman spectra of aragonite, strontianite and witherite. Indian Academy of Sciences [link]
• BENY C. (1989) - Societe Francaise de Mineralogie et de Cristallographie - Base donnees de spectres Raman. Witherite [link]