Keywords:magma, partial molar volume, density, mantle, high pressure
Previous studies indicate the high concentration of Fe2O3 in the lower mantle. Even though the partial molar volume of Fe2O3 has become essential for discussing the magma in the deep mantle, there is no data of partial molar volume of Fe2O3 at high pressure and temperature. This study is aimed to obtain partial molar volume of Fe2O3 in silicate melts under high pressure. Fe3+-rich starting material was compressed by a Kawai-type multi-anvil apparatus at high pressure of above 4 GPa and high-temperature of above 1800 °C. We determined the third-order Birch-Murnaghan equation of state of melts from results of sink-float method. By combining the compression curves of melts and the equation of state of silicate melts proposed in Wakabayashi and Funamori (2013), partial molar volumes were yielded between 8 and 22 GPa and 1800 °C. These results indicate that compressibility of Fe2O3 is much higher than that of FeO within the range of 8 GPa to 22 GPa.