title: Vibrational spectroscopic characterization of the phosphate mineral kulanite Ba(Fe(2+),Mn(2+),Mg)2(Al,Fe(3+))2(PO4)3(OH)3.
abstract: The mineral kulanite BaFe2Al2(PO4)3(OH)3, a barium iron aluminum phosphate, has been studied by using a combination of electron microscopy and vibrational spectroscopy. Scanning electron microscopy with EDX shows the mineral is homogenous with no other phases present. The Raman spectrum is dominated by an intense band at 1022cm(-1) assigned to the PO4(3-)ν1 symmetric stretching mode. Low intensity Raman bands at 1076, 1110, 1146, 1182cm(-1) are attributed to the PO4(3-)ν3 antisymmetric stretching vibrations. The infrared spectrum shows a complex spectral profile with overlapping bands. Multiple phosphate bending vibrations supports the concept of a reduction in symmetry of the phosphate anion. Raman spectrum at 3211, 3513 and 3533cm(-1) are assigned to the stretching vibrations of the OH units. Vibrational spectroscopy enables aspects on the molecular structure of kulanite to be assessed.
authors.affiliation: School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001 Australia. r.frost@qut.edu.au
authors.forename: Ray L
authors.initials: RL
authors.lastname: Frost
authors.forename: Andrés
authors.initials: A
authors.lastname: López
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Xi
authors.forename: Amanda
authors.initials: A
authors.lastname: Granja
authors.forename: Ricardo
authors.initials: R
authors.lastname: Scholz
mesh_terms: D008670:Metals / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008903:Minerals / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D014732:Vibration
chemical_list: D008670:Metals; D008903:Minerals; D010710:Phosphates
keywords: Infrared spectroscopy; Kulanite; Phosphate; Raman spectroscopy