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Raman spectroscopic study of the antimony bearing mineral langbanite
Spectrochimica Acta Part A 75 (2010) 710–712
Contents lists available at ScienceDirect
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy journal homepage: www.elsevier.com/locate/saa
Raman spectroscopic study of the antimony bearing mineral langbanite Silmarilly Bahfenne, Ray L. Frost ∗ Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane , Queensland 4001, Australia
a r t i c l e
i n f o
Article history: Received 31 March 2009 Received in revised form 16 November 2009 Accepted 18 November 2009 Keywords: Langbanite Antimonite Raman spectroscopy Infrared spectroscopy
a b s t r a c t Raman spectroscopy has been used to characterise the antimonate mineral langbanite (Mn, Ca, Fe)4 2+ (Mn3+ , Fe3+ )9 Sb5+ Si2 O24 . The mineral is characterised by a series of peaks in the 850–1200 cm−1 region. Raman bands observed at 872 and 897 cm−1 are assigned to SbO antisymmetric and symmetric stretching vibrations, respectively. Associated with the SbO units are the bands at 330, 351 and 386 cm−1 attributed to OSbO bending modes. Four Raman bands observed at 964, 986, 1012 and 1034 cm−1 are assigned to SiO stretching vibrations. The observation of multiple SiO Raman bands provides evidence for the non-equivalence of the SiO units in the langbanite structure. Associated with the SiO units are the Raman bands at 542, 558, 646 and 671 cm−1 attributed to OSiO bending modes. Low intensity bands are observed at 1130, 1200, 1432, 1718 and 1947 cm−1 and are probably associated with ␦ SbOH deformation modes. Raman bands are observed at 3076 and 3476 cm−1 and are assigned to strongly bonded water molecules involved in the langbanite structure. A sharp Raman band at 3680 cm−1 are assigned to OH stretching vibrations. Raman spectroscopy provides evidence for water and OH units in the structure of langbanite and brings the formula of the mineral into question. © 2009 Elsevier B.V. All rights reserved.
1. Introduction The mineral langbanite [1–3] is a black coloured mineral of formula (Mn, Ca, Fe)4 2+ (Mn3+ , Fe3+ )9 Sb5+ Si2 O24 . Langbanite is an iron-black hexagonal mineral composed of silicate and oxides of manganese, iron, and antimony, occurring in prismatic crystals. The mineral is monoclinic–prismatic H-M Symbol (2/m) Space Group: C 2/m and is black in appearance [3–5]. Giuseppetti et al. [5] reported the structure of langbanite as monoclinic (a = 11.56, b = 20.05, and c = 11.075 Å, 90.03 Å, space group C2/m, Z = 6). The trigonal structure is changed in the monoclinic structure by the 180Â◦ rotation of one for each three Si tetrahedra and by the partial substitution of Fe3+ for Mn3+ and Ca for Mn2+ in distinct sites [5]. The structure of langbanite is founded on the stacking along [0 0 1] of three different layers of polyhedra (Si tetrahedra, Sb5+ octahedra, Mn2+ octahedra) and cubes, Mn3+ octahedra, some of which become polyhedra with coordination 4 (planar) or 5 (tetragonal pyramid) in the monoclinic structure [5]. Farmer reported the infrared spectra of some synthetic antimony bearing compounds (see page 413 and 414 with Tables 17. XVIII and XIX) [6]. For the synthetic compound NaSb(OH)6 which is a compound with an octahedral structure, infrared bands were observed at 600 and 628 cm−1 (very intense), 735 and 775 cm−1 (medium intensity), and 528 and 586 cm−1 . Siebert researched
∗ Corresponding author. Tel.: +61 7 3138 2407; fax: +61 7 3138 1804. E-mail address: [email protected] (R.L. Frost). 1386-1425/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.saa.2009.11.043
the infrared spectra of selected synthetic antimonates [7,8] and assigned bands in the 528–775 cm−1 region to the stretching vibrations of SbO units; in the 1030–1120 cm−1 to the deformation modes of SbOH units and in the 3220–3400 cm−1 to the stretching bands of SbOH and water units. It is interesting to note that only very few papers have been published on the spectroscopy of antimonate minerals. What research has been published is related to the analysis of pigments [9–11]. Some spectroscopic studies of calcium and lead antimonates have been forthcoming [12–14]. Very few studies of related minerals such as mineral antimonates have not been undertaken [15–17]. It was found that the hydroxyl unit was coordinated directly to the metal ion and formed hydrogen bonds to the arsenate anion [18]. As part of a comprehensive study of the molecular structure of minerals containing oxyanions using IR and Raman spectroscopy, we report the Raman properties of the antimonate bearing mineral langbanite. 2. Experimental 2.1. Minerals The mineral langbanite was supplied by Museum South Australia. The mineral originated from Långban mine, Bergslagen ore district, Filipstad, Värmland (Wermland), Sweden. Mn2+ 3.7 Ca0.3 Mn3+ 7.2 Fe3+ 1.4 Mn2+ 0.3 Sb1.2 Si2 O24. The chemical analysis of this mineral has been published [19].
S. Bahfenne, R.L. Frost / Spectrochimica Acta Part A 75 (2010) 710–712
711
Fig. 1. Raman spectrum of Langbanite in the 100–1300 cm−1 region.
2.2. Raman spectroscopy The crystals of langbanite were placed and oriented on the stage of an Olympus BHSM microscope, equipped with 10× and 50× objectives and part of a Renishaw 1000 Raman microscope system, which also includes a monochromator, a filter system and a charge coupled device (CCD). Band component analysis was undertaken using the Jandel ‘Peakfit’ (Erkrath, Germany) software package which enabled the type of fitting function to be selected and allowed specific parameters to be fixed or varied accordingly. Band fitting was done using a Lorentz–Gauss cross-product function with the minimum number of component bands used for the fitting process. The Lorentz–Gauss ratio was maintained at values greater than 0.7 and fitting was undertaken until reproducible results were obtained with squared correlations (r2 ) greater than 0.995. Band fitting of the spectra is quite reliable providing there is some band separation or changes in the spectral profile. 3. Results and discussion The mineral langbanite may be thought of as a complex mixed oxide. Thus the bands in the vibrational spectra may be attributed
to these oxides. The infrared spectra of langbanite have been published (in Russian) [20]. The Raman spectrum of langbanite in the 100–1300 cm−1 region is shown in Fig. 1. The labelled bands in the 870–1200 cm−1 region may be assigned as follows: (a) The band at 872 and 897 cm−1 are assigned to the antisymmetric and symmetric SbO stretching vibrations. (b) Raman bands at 964 and 986 cm−1 are attributed to symmetric SiO stretching vibrations. (c) The bands at 1012 and 1034 cm−1 to the antisymmetric SiO stretching vibrations. (d) The bands at 1130 and 1200 cm−1 are assigned to OH deformation modes associated with SbOH units. The labelled bands in the 200–700 cm−1 region may be assigned as follows: (e) The bands at 330, 351 and 386 cm−1 are assigned to OSbO bending modes. (f) The bands at 415 and 463 cm−1 are associated with MO stretching vibrations where M is Fe, Mn or Ca.
Fig. 2. Raman spectrum of Langbanite in the 1300–4000 cm−1 region.
712
S. Bahfenne, R.L. Frost / Spectrochimica Acta Part A 75 (2010) 710–712
(g) The bands at 542 and 558 cm−1 are assigned to OSiO bending modes. According to Siebert [7,8] all bands in the 800–900 cm−1 are assignable to SbO stretching vibrations. The observation of multiple bands in the Raman spectrum provides evidence for the nonequivalence of SbO units in the langbanite structure. In the infrared spectrum of antimony pentoxide an intense band is observed at 740 cm−1 and low intensity bands are observed at ∼370, 450 and 680 cm−1 [21]. The infrared spectrum of valentinite (Sb2 O3 )4 showed bands in similar positions [21]. Farmer reported the band positions of synthetic antimonates of formula MSbO4 where M is Cr, Fe, Ga or Rh with a rutile type structure [6]. As such these structures should have four Raman active bands (A1g + B1g + B2g + Eg ) and four infrared active bands (A2u + 3Eu ). Infrared bands were observed in the 660–735 cm−1 , 520–585 cm−1 , 285–375 cm−1 and 170–190 cm−1 . Although no assignment was given to these bands but one possible interpretation is that the first band is attributed to the antisymmetric stretching mode, the second to the symmetric stretching mode, the third to bending modes and the fourth to a lattice modes. The Raman spectrum of langbanite in the 1300–3800 cm−1 region is displayed in Fig. 2. This spectrum is quite interesting because according to the formula no bands in the OH stretching region are expected. Two broad bands are observed at 3076 and 3476 cm−1 which may be attributed to water stretching vibrations. A sharp band is observed at 3680 cm−1 which is attributed to an OH stretching band. Other low intensity bands observed at 1432, 1718 and 1947 cm−1 may be assigned to OH deformation vibrations of MOH units where M is a heavy metal cation. Siebert reported four infrared bands at 1030, 1075, 1105 and 1120 cm−1 for the synthetic compound NaSb(OH)6 . The position and number of these Raman bands for this compound is in good agreement with the position of the Raman bands of langbanite. An alternative assignment is that these bands are combination or overtone bands. However this seems unlikely. The observation of these bands in the 1030–1120 cm−1 region, brings in to question the actual formula of the mineral langbanite. The formula is given by (Mn, Ca, Fe)4 2+ (Mn3+ , Fe3+ )9 Sb5+ Si2 O24 . Raman spectroscopy appears to indicate that both water and OH units are involved in the structure. Strunz did some calculations based upon the analyses of langbanite and questioned the formula of the mineral [22]. This work confirms the conclusions of Strunz. 4. Conclusions The mineral langbanite has been studied by Raman spectroscopy. The mineral has classically been given the formula mineral (Mn, Ca, Fe)4 2+ (Mn3+ , Fe3+ )9 Sb5+ Si2 O24 . However Raman spectroscopy identifies bands assignable to water stretching and bending vibrations. Further the observation of ␦ SbOH deforma-
tion modes 1130, 1200, 1432, 1718 and 1947 cm−1 forms the basis of hydroxyl units being involved in the mineral structure. The observation of two bands at 3076 and 3476 cm−1 suggests that water is involved in the structure of langbanite and the formula is better written (Mn, Ca, Fe)4 2+ (Mn3+ , Fe3+ )9 Sb5+ (OH,H2 O) Si2 O24 . Raman spectroscopy provides evidence for water and OH units in the structure of langbanite and brings the formula of the mineral into question as has been suggested by Strunz, some considerable time ago. Intense Raman bands at 872 and 897 cm−1 are assigned to SbO stretching vibrations. Strong Raman bands at 330, 351 and 386 cm−1 attributed to OSbO bending modes. Raman observed at 964, 986, 1012 and 1034 cm−1 are assigned to SiO stretching vibrations. Raman bands at 542, 558, 646 and 671 cm−1 attributed to OSiO bending modes. Acknowledgements The financial and infra-structure support of the Queensland University of Technology Inorganic Materials Research Program of the School of Physical and Chemical Sciences is gratefully acknowledged. The Australian Research Council (ARC) is thanked for funding the instrumentation. References [1] [2] [3] [4] [5] [6] [7] [8]
[9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22]
G. Flink, 58 (1923) 356-385. E.N. Kurkutova, V.G. Rau, Strukt. Svoistva Krist. 1 (1974) 53–69. F. Machatschki, Neues Jahrb. Min. 1943A (1943) 46–47. P.B. Moore, P.K. Sen Gupta, Y. Le Page, Am. Min. 76 (1991) 1408–1425. H. Moazed, Removal of oil from water by organo-clay and other sorbents, PhD Thesis, Univ. of Regina, Regina, SK, Can. V.C. Farmer, Mineralogical Society Monograph 4: The Infrared Spectra of Minerals, The Mineralogical Society, London, 1974. H. Siebert, Z. Anorg. U. Allgem. Chem. 301 (1959) 161–170. H. Siebert, Anwendungen der Schwingungsspektroskopie in der Anorganischen Chemie (Anorganische und Allgemeine Chemie in Einzeldarstellungen, Bd. 7) (Application of Vibrational Spectroscopy in Inorganic Chemistry (Monographs in Inorganic and General Chemistry, Vol. 7)), 1966. A.M. Correia, M.J.V. Oliveira, R.J.H. Clark, M.I. Ribeiro, M.L. Duarte, Anal. Chem. 80 (2008) 1482–1492. A.M. Correia, R.J.H. Clark, M.I.M. Ribeiro, M.L.T.S. Duarte, J. Raman Spectrosc. 38 (2007) 1390–1405. R.J.H. Clark, L. Cridland, B.M. Kariuki, K.D.M. Harris, R. Withnall, J. Chem. Soc. (1995) 2577–2582. E. Husson, Y. Repelin, M.T. Vandenborre, Spectrochim. Acta 40A (1984) 1017–1020. H. Haeuseler, Spectrochim. Acta 37A (1981) 487–495. M.T. Vandenborre, E. Husson, H. Brusset, A. Cerez, Spectrochim. Acta 36A (1980) 1045–1052. M.T. Paques-Ledent, P. Tarte, Spectrochim. Acta 30A (1974) 673–689. S.V. Gevork’yan, A.S. Povarennykh, Konst. Svoistva Miner. 9 (1975) 73–81. R.S.W. Braithwaite, Min. Mag. 47 (1983) 51–57. V.I. Sumin De Portilla, Can. Min. 12 (1974) 262–268. J.W. Anthony, R.A. Bideaux, K.W. Bladh, M.C. Nichols, Handbook of mineralogy, 2000. A.S. Povarennykh, Konstitutsiya i Svoistva Mineralov 13 (1979) 53–78. J.A. Gadsden, Infrared Spectra of Minerals and Related Inorganic Compounds, Buttherworth, London, UK, 1975. H. Strunz, Zentralblatt fuer mineralogie, Geologie und Palaeontologie 1942 A (1942) 133–136.
Contents lists available at ScienceDirect
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy journal homepage: www.elsevier.com/locate/saa
Raman spectroscopic study of the antimony bearing mineral langbanite Silmarilly Bahfenne, Ray L. Frost ∗ Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane , Queensland 4001, Australia
a r t i c l e
i n f o
Article history: Received 31 March 2009 Received in revised form 16 November 2009 Accepted 18 November 2009 Keywords: Langbanite Antimonite Raman spectroscopy Infrared spectroscopy
a b s t r a c t Raman spectroscopy has been used to characterise the antimonate mineral langbanite (Mn, Ca, Fe)4 2+ (Mn3+ , Fe3+ )9 Sb5+ Si2 O24 . The mineral is characterised by a series of peaks in the 850–1200 cm−1 region. Raman bands observed at 872 and 897 cm−1 are assigned to SbO antisymmetric and symmetric stretching vibrations, respectively. Associated with the SbO units are the bands at 330, 351 and 386 cm−1 attributed to OSbO bending modes. Four Raman bands observed at 964, 986, 1012 and 1034 cm−1 are assigned to SiO stretching vibrations. The observation of multiple SiO Raman bands provides evidence for the non-equivalence of the SiO units in the langbanite structure. Associated with the SiO units are the Raman bands at 542, 558, 646 and 671 cm−1 attributed to OSiO bending modes. Low intensity bands are observed at 1130, 1200, 1432, 1718 and 1947 cm−1 and are probably associated with ␦ SbOH deformation modes. Raman bands are observed at 3076 and 3476 cm−1 and are assigned to strongly bonded water molecules involved in the langbanite structure. A sharp Raman band at 3680 cm−1 are assigned to OH stretching vibrations. Raman spectroscopy provides evidence for water and OH units in the structure of langbanite and brings the formula of the mineral into question. © 2009 Elsevier B.V. All rights reserved.
1. Introduction The mineral langbanite [1–3] is a black coloured mineral of formula (Mn, Ca, Fe)4 2+ (Mn3+ , Fe3+ )9 Sb5+ Si2 O24 . Langbanite is an iron-black hexagonal mineral composed of silicate and oxides of manganese, iron, and antimony, occurring in prismatic crystals. The mineral is monoclinic–prismatic H-M Symbol (2/m) Space Group: C 2/m and is black in appearance [3–5]. Giuseppetti et al. [5] reported the structure of langbanite as monoclinic (a = 11.56, b = 20.05, and c = 11.075 Å, 90.03 Å, space group C2/m, Z = 6). The trigonal structure is changed in the monoclinic structure by the 180Â◦ rotation of one for each three Si tetrahedra and by the partial substitution of Fe3+ for Mn3+ and Ca for Mn2+ in distinct sites [5]. The structure of langbanite is founded on the stacking along [0 0 1] of three different layers of polyhedra (Si tetrahedra, Sb5+ octahedra, Mn2+ octahedra) and cubes, Mn3+ octahedra, some of which become polyhedra with coordination 4 (planar) or 5 (tetragonal pyramid) in the monoclinic structure [5]. Farmer reported the infrared spectra of some synthetic antimony bearing compounds (see page 413 and 414 with Tables 17. XVIII and XIX) [6]. For the synthetic compound NaSb(OH)6 which is a compound with an octahedral structure, infrared bands were observed at 600 and 628 cm−1 (very intense), 735 and 775 cm−1 (medium intensity), and 528 and 586 cm−1 . Siebert researched
∗ Corresponding author. Tel.: +61 7 3138 2407; fax: +61 7 3138 1804. E-mail address: [email protected] (R.L. Frost). 1386-1425/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.saa.2009.11.043
the infrared spectra of selected synthetic antimonates [7,8] and assigned bands in the 528–775 cm−1 region to the stretching vibrations of SbO units; in the 1030–1120 cm−1 to the deformation modes of SbOH units and in the 3220–3400 cm−1 to the stretching bands of SbOH and water units. It is interesting to note that only very few papers have been published on the spectroscopy of antimonate minerals. What research has been published is related to the analysis of pigments [9–11]. Some spectroscopic studies of calcium and lead antimonates have been forthcoming [12–14]. Very few studies of related minerals such as mineral antimonates have not been undertaken [15–17]. It was found that the hydroxyl unit was coordinated directly to the metal ion and formed hydrogen bonds to the arsenate anion [18]. As part of a comprehensive study of the molecular structure of minerals containing oxyanions using IR and Raman spectroscopy, we report the Raman properties of the antimonate bearing mineral langbanite. 2. Experimental 2.1. Minerals The mineral langbanite was supplied by Museum South Australia. The mineral originated from Långban mine, Bergslagen ore district, Filipstad, Värmland (Wermland), Sweden. Mn2+ 3.7 Ca0.3 Mn3+ 7.2 Fe3+ 1.4 Mn2+ 0.3 Sb1.2 Si2 O24. The chemical analysis of this mineral has been published [19].
S. Bahfenne, R.L. Frost / Spectrochimica Acta Part A 75 (2010) 710–712
711
Fig. 1. Raman spectrum of Langbanite in the 100–1300 cm−1 region.
2.2. Raman spectroscopy The crystals of langbanite were placed and oriented on the stage of an Olympus BHSM microscope, equipped with 10× and 50× objectives and part of a Renishaw 1000 Raman microscope system, which also includes a monochromator, a filter system and a charge coupled device (CCD). Band component analysis was undertaken using the Jandel ‘Peakfit’ (Erkrath, Germany) software package which enabled the type of fitting function to be selected and allowed specific parameters to be fixed or varied accordingly. Band fitting was done using a Lorentz–Gauss cross-product function with the minimum number of component bands used for the fitting process. The Lorentz–Gauss ratio was maintained at values greater than 0.7 and fitting was undertaken until reproducible results were obtained with squared correlations (r2 ) greater than 0.995. Band fitting of the spectra is quite reliable providing there is some band separation or changes in the spectral profile. 3. Results and discussion The mineral langbanite may be thought of as a complex mixed oxide. Thus the bands in the vibrational spectra may be attributed
to these oxides. The infrared spectra of langbanite have been published (in Russian) [20]. The Raman spectrum of langbanite in the 100–1300 cm−1 region is shown in Fig. 1. The labelled bands in the 870–1200 cm−1 region may be assigned as follows: (a) The band at 872 and 897 cm−1 are assigned to the antisymmetric and symmetric SbO stretching vibrations. (b) Raman bands at 964 and 986 cm−1 are attributed to symmetric SiO stretching vibrations. (c) The bands at 1012 and 1034 cm−1 to the antisymmetric SiO stretching vibrations. (d) The bands at 1130 and 1200 cm−1 are assigned to OH deformation modes associated with SbOH units. The labelled bands in the 200–700 cm−1 region may be assigned as follows: (e) The bands at 330, 351 and 386 cm−1 are assigned to OSbO bending modes. (f) The bands at 415 and 463 cm−1 are associated with MO stretching vibrations where M is Fe, Mn or Ca.
Fig. 2. Raman spectrum of Langbanite in the 1300–4000 cm−1 region.
712
S. Bahfenne, R.L. Frost / Spectrochimica Acta Part A 75 (2010) 710–712
(g) The bands at 542 and 558 cm−1 are assigned to OSiO bending modes. According to Siebert [7,8] all bands in the 800–900 cm−1 are assignable to SbO stretching vibrations. The observation of multiple bands in the Raman spectrum provides evidence for the nonequivalence of SbO units in the langbanite structure. In the infrared spectrum of antimony pentoxide an intense band is observed at 740 cm−1 and low intensity bands are observed at ∼370, 450 and 680 cm−1 [21]. The infrared spectrum of valentinite (Sb2 O3 )4 showed bands in similar positions [21]. Farmer reported the band positions of synthetic antimonates of formula MSbO4 where M is Cr, Fe, Ga or Rh with a rutile type structure [6]. As such these structures should have four Raman active bands (A1g + B1g + B2g + Eg ) and four infrared active bands (A2u + 3Eu ). Infrared bands were observed in the 660–735 cm−1 , 520–585 cm−1 , 285–375 cm−1 and 170–190 cm−1 . Although no assignment was given to these bands but one possible interpretation is that the first band is attributed to the antisymmetric stretching mode, the second to the symmetric stretching mode, the third to bending modes and the fourth to a lattice modes. The Raman spectrum of langbanite in the 1300–3800 cm−1 region is displayed in Fig. 2. This spectrum is quite interesting because according to the formula no bands in the OH stretching region are expected. Two broad bands are observed at 3076 and 3476 cm−1 which may be attributed to water stretching vibrations. A sharp band is observed at 3680 cm−1 which is attributed to an OH stretching band. Other low intensity bands observed at 1432, 1718 and 1947 cm−1 may be assigned to OH deformation vibrations of MOH units where M is a heavy metal cation. Siebert reported four infrared bands at 1030, 1075, 1105 and 1120 cm−1 for the synthetic compound NaSb(OH)6 . The position and number of these Raman bands for this compound is in good agreement with the position of the Raman bands of langbanite. An alternative assignment is that these bands are combination or overtone bands. However this seems unlikely. The observation of these bands in the 1030–1120 cm−1 region, brings in to question the actual formula of the mineral langbanite. The formula is given by (Mn, Ca, Fe)4 2+ (Mn3+ , Fe3+ )9 Sb5+ Si2 O24 . Raman spectroscopy appears to indicate that both water and OH units are involved in the structure. Strunz did some calculations based upon the analyses of langbanite and questioned the formula of the mineral [22]. This work confirms the conclusions of Strunz. 4. Conclusions The mineral langbanite has been studied by Raman spectroscopy. The mineral has classically been given the formula mineral (Mn, Ca, Fe)4 2+ (Mn3+ , Fe3+ )9 Sb5+ Si2 O24 . However Raman spectroscopy identifies bands assignable to water stretching and bending vibrations. Further the observation of ␦ SbOH deforma-
tion modes 1130, 1200, 1432, 1718 and 1947 cm−1 forms the basis of hydroxyl units being involved in the mineral structure. The observation of two bands at 3076 and 3476 cm−1 suggests that water is involved in the structure of langbanite and the formula is better written (Mn, Ca, Fe)4 2+ (Mn3+ , Fe3+ )9 Sb5+ (OH,H2 O) Si2 O24 . Raman spectroscopy provides evidence for water and OH units in the structure of langbanite and brings the formula of the mineral into question as has been suggested by Strunz, some considerable time ago. Intense Raman bands at 872 and 897 cm−1 are assigned to SbO stretching vibrations. Strong Raman bands at 330, 351 and 386 cm−1 attributed to OSbO bending modes. Raman observed at 964, 986, 1012 and 1034 cm−1 are assigned to SiO stretching vibrations. Raman bands at 542, 558, 646 and 671 cm−1 attributed to OSiO bending modes. Acknowledgements The financial and infra-structure support of the Queensland University of Technology Inorganic Materials Research Program of the School of Physical and Chemical Sciences is gratefully acknowledged. The Australian Research Council (ARC) is thanked for funding the instrumentation. References [1] [2] [3] [4] [5] [6] [7] [8]
[9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22]
G. Flink, 58 (1923) 356-385. E.N. Kurkutova, V.G. Rau, Strukt. Svoistva Krist. 1 (1974) 53–69. F. Machatschki, Neues Jahrb. Min. 1943A (1943) 46–47. P.B. Moore, P.K. Sen Gupta, Y. Le Page, Am. Min. 76 (1991) 1408–1425. H. Moazed, Removal of oil from water by organo-clay and other sorbents, PhD Thesis, Univ. of Regina, Regina, SK, Can. V.C. Farmer, Mineralogical Society Monograph 4: The Infrared Spectra of Minerals, The Mineralogical Society, London, 1974. H. Siebert, Z. Anorg. U. Allgem. Chem. 301 (1959) 161–170. H. Siebert, Anwendungen der Schwingungsspektroskopie in der Anorganischen Chemie (Anorganische und Allgemeine Chemie in Einzeldarstellungen, Bd. 7) (Application of Vibrational Spectroscopy in Inorganic Chemistry (Monographs in Inorganic and General Chemistry, Vol. 7)), 1966. A.M. Correia, M.J.V. Oliveira, R.J.H. Clark, M.I. Ribeiro, M.L. Duarte, Anal. Chem. 80 (2008) 1482–1492. A.M. Correia, R.J.H. Clark, M.I.M. Ribeiro, M.L.T.S. Duarte, J. Raman Spectrosc. 38 (2007) 1390–1405. R.J.H. Clark, L. Cridland, B.M. Kariuki, K.D.M. Harris, R. Withnall, J. Chem. Soc. (1995) 2577–2582. E. Husson, Y. Repelin, M.T. Vandenborre, Spectrochim. Acta 40A (1984) 1017–1020. H. Haeuseler, Spectrochim. Acta 37A (1981) 487–495. M.T. Vandenborre, E. Husson, H. Brusset, A. Cerez, Spectrochim. Acta 36A (1980) 1045–1052. M.T. Paques-Ledent, P. Tarte, Spectrochim. Acta 30A (1974) 673–689. S.V. Gevork’yan, A.S. Povarennykh, Konst. Svoistva Miner. 9 (1975) 73–81. R.S.W. Braithwaite, Min. Mag. 47 (1983) 51–57. V.I. Sumin De Portilla, Can. Min. 12 (1974) 262–268. J.W. Anthony, R.A. Bideaux, K.W. Bladh, M.C. Nichols, Handbook of mineralogy, 2000. A.S. Povarennykh, Konstitutsiya i Svoistva Mineralov 13 (1979) 53–78. J.A. Gadsden, Infrared Spectra of Minerals and Related Inorganic Compounds, Buttherworth, London, UK, 1975. H. Strunz, Zentralblatt fuer mineralogie, Geologie und Palaeontologie 1942 A (1942) 133–136.