Over 1 Mbar generation in the Kawai-type multianvil apparatus and its application to compression of (Mg0.92Fe0.08)SiO3 perovskite and stishovite

• Pressure was generated up to 109.3 GPa in a Kawai-type multianvil apparatus.
• KT0 and K0′ were determined to be 268 GPa and 3.8, respectively, for perovskite.
• Stishovite transforms to the CaCl2-type phase at ∼54 GPa at 300 K.

We generated pressures up to 109.3 GPa in a Kawai-type multianvil apparatus (KMA) equipped with sintered diamond anvils by means of in situ X-ray observation with synchrotron radiation. The unit cell parameters of (Mg0.92Fe0.08)SiO3 perovskite, SiO2 stishovite, and the CaCl2-type polymorph of SiO2 were measured as functions of pressure. We determined the isothermal bulk modulus, KT0, and its pressure derivative, K0′, at zero pressure, to be 268 (3) GPa and 3.8 (0.1), respectively, for (Mg0.92Fe0.08)SiO3 perovskite. Stishovite transforms to the CaCl2-type phase at approximately 54 GPa at 300 K. Compression through stishovite and the CaCl2-type phase can be represented by a single compression curve with KT0 = 299 (4) GPa and K0′=4.6(0.2).