TY - JOUR A1 - Thünemann, Andreas A1 - Kubowicz, S. A1 - Geue, T. M. A1 - Pietsch, U. A1 - Watson, M. D. A1 - Tchebotareva, N. A1 - Müllen, K. T1 - X-ray reflectivity study of an amphiphilic hexa-peri-hexabenzocoronene at a structured silicon wafer surface KW - Discotic Liquid Crystals KW - Thin Organic Films PY - 2003 DO - https://doi.org/10.1021/la035210e SN - 0743-7463 SN - 1520-5827 VL - 19 IS - 26 SP - 10997 EP - 10999 PB - American Chemical Society CY - Washington, DC AN - OPUS4-2846 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gabitov, R.I. A1 - Schmitt, A.K. A1 - Rosner, Martin A1 - McKeegan, K.D. A1 - Gaetani, G.A. A1 - Cohen, A.L. A1 - Watson, E.B. A1 - Harrison, T.M. T1 - In situ delta7Li, Li/Ca, and Mg/Ca analyses of synthetic aragonites N2 - In situ secondary ion mass spectrometry (SIMS) analyses of δ7Li, Li/Ca, and Mg/Ca were performed on five synthetic aragonite samples precipitated from seawater at 25°C at different rates. The compositions of δ7Li in bulk aragonites and experimental fluids were measured by multicollector inductively coupled plasma–mass spectrometry (MC-ICP-MS). Both techniques yielded similar δ7Li in aragonite when SIMS analyses were corrected to calcium carbonate reference materials. Fractionation factors α7Li/6Li range from 0.9895 to 0.9923, which translates to a fractionation between aragonite and fluid from -10.5‰ to -7.7‰. The within-sample δ7Li range determined by SIMS is up to 27‰, exceeding the difference between bulk δ7Li analyses of different aragonite precipitates. Moreover, the centers of aragonite hemispherical bundles (spherulites) are enriched in Li/Ca and Mg/Ca relative to spherulite fibers by up to factors of 2 and 8, respectively. The Li/Ca and Mg/Ca ratios of spherulite fibers increase with aragonite precipitation rate. These results suggest that precipitation rate is a potentially important consideration when using Li isotopes and elemental ratios in natural carbonates as a proxy for seawater composition and temperature. KW - Lithium KW - Isotope KW - Aragonite KW - Rate KW - SIMS KW - Magnesium PY - 2011 DO - https://doi.org/10.1029/2010GC003322 SN - 1525-2027 VL - 12 IS - 3 (Technical Brief) SP - 1 EP - 16 CY - Washington, DC, USA AN - OPUS4-23312 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -