Raman spectroscopic study of the antimony bearing mineral langbanite.
Raman spectroscopy has been used to characterise the antimonate mineral langbanite (Mn, Ca, Fe)(4)(2+)(Mn(3+), Fe(3+))(9)Sb(5+)Si(2)O(24). The mineral is characterised by a series of peaks in the 850-1200 cm(-1) region. Raman bands observed at 872 and 897cm(-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 delta 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.
Bahfenne
Silmarilly
S
Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia.
Frost
Ray L
RL
D000965:Antimony / Q000737:chemistry*; D003460:Crystallization; D008670:Metals / Q000737:chemistry*; D008903:Minerals / Q000737:chemistry*; D013059:Spectrum Analysis, Raman
D008670:Metals; D008903:Minerals; D000965:Antimony