Al,H-bearing stishovite has been exceptionally interesting for high

performed Brillouin and Raman scattering measurements on stishovite with various Al ... respectively. An anomalous softening of elastic constant C12 supports.
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Effect of Al and H on elasticity of stishovite D. LAKSHTANOV University of Illinois at Urbana-Champaign, USA

Al,H-bearing stishovite has been exceptionally interesting for highpressure mineral physics as one of the possible means of water transport into the lower mantle. Also, being excessively experimentally studied for the last 40 years, stishovite has become a classic modeling system. We have performed Brillouin and Raman scattering measurements on stishovite with various Al3+ and H+ content and determined the effect of these impurities on density, acoustic velocities, single-crystal and aggregate elastic moduli. Our data show an overall relatively linear drop of the K0 to 290 GPa at alumina and water content of 6.07(5) and 0.47(7) wt% respectively. An anomalous softening of elastic constant C12 supports placement of H+ atom in basal plane of stishovite, as well as a hypothesis of asymmetric nature of hydrogen bonding in Al,H-bearing stishovite at ambient pressure.