bmim]Cl/FeCl3 ionic liquids (where bmim = 1-butyl-3-methylimidazolium) were characterized by XPS (X-ray photoelectron spectroscopy), FT-IR (Fourier transform infrared spectroscopy), Raman and NMR (nuclear magnetic r...bmim]Cl/FeCl3 ionic liquids (where bmim = 1-butyl-3-methylimidazolium) were characterized by XPS (X-ray photoelectron spectroscopy), FT-IR (Fourier transform infrared spectroscopy), Raman and NMR (nuclear magnetic resonance) spectra. The results show that Fe2Cl7 and FeCl4 ions are the principal anions in acidic ionic liquids, - - whose concentrations change with the content of FeCl3 and an equilibrium exists between them. An isosbestic point existing in FT-IR spectra indicates that an interaction involving at least two species occurs and their concentrations vary with acidity. Chemical shifts of the hydrogen located in the cations of ionic liquids are sensitive to the composition of ionic liquids. The change in chemical shifts may be explained in terms of anion-cation interactions. The chemical shifts of 2-H are affected by metal halides, which shift downfield and the 2-H is more deshielded with the increase in metal halides.展开更多
Garnet is one of the most significant minerals in metamorphic rocks, that provides key information on prograde, peak-metamorphic and retrograde parts of the pressure-temperature （PT） path. Such results require a det...Garnet is one of the most significant minerals in metamorphic rocks, that provides key information on prograde, peak-metamorphic and retrograde parts of the pressure-temperature （PT） path. Such results require a detailed knowledge of its different growth domains. For iron-poor compositions, the cathodoluminescence （CL） microscopy is an important and often overlooked method and allows to identify the internal structures of all garnet grains in one thin section within only a few seconds. The advantage of the CL-microscope is to deliver low magnification images in true color, not only of garnet but also, for instance, of other rock forming silicates, carbonates, sulfates, etc., of metamorphic, but also of sedimentary and magmatic origin, using polished thin sections. Internal structures of grossular from Mexico and pyrope from the Italian Alps were characterized and visualized by CL-microscopy. The different growth domains were additionally studied using CL-spectra and electron microprobe （EMP） analysis. Grossular shows a patchy zonation in its core while in mantle and rim zones oscillatory zoning is observed. It contains zones of anomalous birefringence, zones of orange and bluish luminescence and zones lacking luminescence. Different but low amounts of the activator elements Mn2＋ and Eu2＋ are responsible for the orange and bluish luminescent domains. Pyrope is also characterized by oscillatory growth zones, shows a dull luminescent core with a change of crystal morphology during growth, and displays an increase of brightness from core towards rim--the outermost rim, however, is lacking luminescence. The different luminescent zones are characterized by different amounts of Dy3＋, Tb3＋, Sm3＋ and Sm2＋ as activator elements. Because of slow diffusion rates of activators such as the REEs Sm, Dy and Tb, it can be still possible to visualize possible prograde and/or peak pressure stage growth domains of garnet, even if later high temperature events may have homogenized the major element profiles. Such domains may help to identify respective assemblages of mineral inclusions, and hence these results can represent an integral part of a detailed PT path. Thus the CL-information can be used as an important pathfinder prior to supplementary investigations, as for instance EMP, ion probe, mineral or fluid inclusion studies.展开更多
文摘bmim]Cl/FeCl3 ionic liquids (where bmim = 1-butyl-3-methylimidazolium) were characterized by XPS (X-ray photoelectron spectroscopy), FT-IR (Fourier transform infrared spectroscopy), Raman and NMR (nuclear magnetic resonance) spectra. The results show that Fe2Cl7 and FeCl4 ions are the principal anions in acidic ionic liquids, - - whose concentrations change with the content of FeCl3 and an equilibrium exists between them. An isosbestic point existing in FT-IR spectra indicates that an interaction involving at least two species occurs and their concentrations vary with acidity. Chemical shifts of the hydrogen located in the cations of ionic liquids are sensitive to the composition of ionic liquids. The change in chemical shifts may be explained in terms of anion-cation interactions. The chemical shifts of 2-H are affected by metal halides, which shift downfield and the 2-H is more deshielded with the increase in metal halides.
文摘Garnet is one of the most significant minerals in metamorphic rocks, that provides key information on prograde, peak-metamorphic and retrograde parts of the pressure-temperature （PT） path. Such results require a detailed knowledge of its different growth domains. For iron-poor compositions, the cathodoluminescence （CL） microscopy is an important and often overlooked method and allows to identify the internal structures of all garnet grains in one thin section within only a few seconds. The advantage of the CL-microscope is to deliver low magnification images in true color, not only of garnet but also, for instance, of other rock forming silicates, carbonates, sulfates, etc., of metamorphic, but also of sedimentary and magmatic origin, using polished thin sections. Internal structures of grossular from Mexico and pyrope from the Italian Alps were characterized and visualized by CL-microscopy. The different growth domains were additionally studied using CL-spectra and electron microprobe （EMP） analysis. Grossular shows a patchy zonation in its core while in mantle and rim zones oscillatory zoning is observed. It contains zones of anomalous birefringence, zones of orange and bluish luminescence and zones lacking luminescence. Different but low amounts of the activator elements Mn2＋ and Eu2＋ are responsible for the orange and bluish luminescent domains. Pyrope is also characterized by oscillatory growth zones, shows a dull luminescent core with a change of crystal morphology during growth, and displays an increase of brightness from core towards rim--the outermost rim, however, is lacking luminescence. The different luminescent zones are characterized by different amounts of Dy3＋, Tb3＋, Sm3＋ and Sm2＋ as activator elements. Because of slow diffusion rates of activators such as the REEs Sm, Dy and Tb, it can be still possible to visualize possible prograde and/or peak pressure stage growth domains of garnet, even if later high temperature events may have homogenized the major element profiles. Such domains may help to identify respective assemblages of mineral inclusions, and hence these results can represent an integral part of a detailed PT path. Thus the CL-information can be used as an important pathfinder prior to supplementary investigations, as for instance EMP, ion probe, mineral or fluid inclusion studies.
