Ultrahochdruck-Vielstempelapparatur
Final Report Abstract
The ultrahigh-pressure multi-anvil press was delivered and installed in the Bayerisches Geoinstitut in September 2014. Thanks to careful setup process and pressure calibration, it became routinely possible to generate pressures up to 25 GPa, which is the maximum pressure generated by usual multi-anvil apparatus, was confirmed in January 2015. Then we developed further high-pressure generation by combining the following techniques: 1) use of hard anvil, 2) anvil tapering, 3) incompressible pressure medium, 4) thermal insulation. Thanks to these developments, pressures exceeding 40 GPa were successfully generated at a high temperature of 2000 K. The maximum pressures were further increased to 65 and 48 GPa at ambient temperature and 2000 K, respectively. These values are the world records of pressure generation of multi-anvil presses with carbide anvils. We demonstrated ultrahigh-pressure generation by synthesis of LiNbO3-type of Mg3Al2Si3O12 at 2000 K. We investigated the maximum oxygen vacancy component (MgAlO2.5) in bridgmanite as a function of pressure and temperature, because this component should soften the lower mantle, and therefore its contents are vital to understand mantle dynamics. Since steep temperature gradients in samples are obstacle to obtain robust results especially in melting experiments, we invented a new furnace assembly to allow nearly zero temperature gradient in a sample. The same type of multi-anvil press was installed in the synchrotron radiation facility, SPring-8. Since beam times of synchrotron radiation facilities are limited, it is necessary to conduct in-house pre-experiments to allow high success rate and well controlled sample environments. We conducted a number of pre-experiments for synchrotron experiments using this apparatus, and successfully determined the post-garnet transition in MgSiO3-Al2O3 and post-spinel transition in Mg2SiO4. We have also developed a high-pressure generation technique using sintered diamond anvils. We generated 50 GPa by this technique. We determined phase relations in garnet to bridgmanite + corundum at temperatures of 1700, 2000 and 2300 K.
Publications
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Generation of pressures over 40 GPa using Kawai-type multi-anvil apparatus with tungsten carbide anvils, Rev. Sci. Instr. 87, 024501
Ishii, T., L.-L. Shi, R. Huang, N. Tsujino, D. Druzhbin, R. Myhill, Y. Li, L. Wang, T. Yamamoto, N. Miyajima, T. Kawazoe, N. Nishiyama, Y. Higo, Y. Tange, and T. Katsura
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2017. Synthesis and crystal structure of LiNbO3-type Mg3Al2Si3O12: A possible indicator of shock conditions of meteorites. Am. Miner. 102, 1947-1952
Ishii, T., Sinmyo, R., Komabayashi, T., Ballaran, T.B., Kawazoe, T., Miyajima, N., Hirose, K., Katsura, T.
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Phase relations in the system MgSiO3– Al2O3 up to 2300 K at lower-mantle pressures. J. Geophys. Res. - Solid Earth, 122., 2017
Liu, Z.-D., M. Nishi, T. Ishii, H.-Z. Fei, N. Miyajima, T. Boffa-Ballaran, H. Ohfuji, T. Sakai, L. Wang, S. Scheka, T. Arimoto, Y. Tange, Y. Higo, T. Irifune and T. Katsura
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Pressure generation to 65 GPa in a Kawai-type multi-anvil apparatus with tungsten carbide anvils. High Press. Res. 37, 507-515, 2017
Ishii, T., Yamazaki, D., Tsujino, N., Xu, F., Liu, Z., Kawazoe, T., Yamamoto, T., Druzhbin, D., Wang, L., Higo, Y., Tange, Y., Yoshino, T., Katsura, T.
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Rapid decrease in oxygen-vacancy substitution in aluminous bridgmanite with pressure, Geochem. Persp. Lett. 5, 12-18, 2017
Liu, Z.-D., T. Ishii and T. Katsura
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2018. A nearly zero temperature gradient furnace system for high pressure multi-anvil experiments. High Pressure Res. 38, 243-249
Zarei, A., Li, Y., Fei, H.Z., Katsura, T.
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2018. Complete agreement of the post-spinel transition with the 660-km seismic discontinuity. Sci Rep-Uk 8, 6358
Ishii, T., Huang, R., Fei, H., Koemets, I., Liu, Z., Maeda, F., Yuan, L., Wang, L., Druzhbin, D., Yamamoto, T., Bhat, S., Farla, R., Kawazoe, T., Tsujino, N., Kulik, E., Higo, Y., Tange, Y., Katsura, T.
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2019. Increase of the oxygen vacancy component in bridgmanite with temperature. Earth Planet. Sci. Lett. 505, 141-151
Liu, Z., Akaogi, M., Katsura, T.
