Silicon Xanes Assessment of the Silicone Oil Content of Gems in Idps
Lunar and Planetary Science XLVIII (2017) 1059.pdf SILICON XANES ASSESSMENT OF THE SILICONE OIL CONTENT OF GEMS IN IDPS . G. J. Flynn 1, S. Wirick 2, A. L. Butterworth 3, Z. Gainsforth3, A. J. Westphal 3, B. Kaulich 4, T. Araki 4, M. Abyaneh 4, and T. Ty- liszczak 5. 1Dept. of Physics, SUNY-Plattsburgh, Plattsburgh, NY 12901 USA ( george.flynn@plattsburgh.edu ), 2Focused Beam Enterprises, Westhampton, NY 11977, 3Space Sciences Laboratory, University of California, Berke- ley, CA 94720, 4Diamond Light Source, Didcot, Oxfordshire OX11 0DE, UK, 5Advanced Light Source, 6 Cyclotron Rd., Berkeley, CA 94720 Introduction: Glass with Embedded Metal and copy, and Si x-ray absorption near-edge structure Sulfides (GEMS) is a major component in many chon- (XANES) spectroscopy provides a technique to assess dritic porous interplanetary dust particles (CP IDPs). the silicone oil content of GEMS. Barranco et al. [8] Based on the similarity of GEMS to the properties of performed Si-XANES on SiO xCyHz polymeric thin interstellar silicates, inferred from astronomical obser- films having compositions with different C/O atomic vations, Bradley [1] proposed that GEMS are surviv- ratios. They also measured Si-XANES spectra of Si- ing interstellar silicates. The GEMS in CP IDPs have carbide and SiO 2 and found that the energy of the onset been extensively studied over the past two decades. of the Si K absorption edge varied with the composi- Synchrotron-based infrared spectroscopy showed a tion from 1840 eV in SiC to 1844 eV in SiO 2. Because good match between the 10 micron Si-O absorption the Si-C and Si-O bonds absorb at significantly differ- feature of GEMS in CP IDPs and the silicates in two ent energies, Si-XANES is a particularly effective molecular clouds as well as in the regions surrounding technique to assess the ratio of Si-C to Si-O bonding at a T-Tauri star and a post-main sequence M star [2].
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