R3: High-pressure science and deep Earth's material

[R3-06] The stability of Fe₅O₆ and Fe₄O₅ at high pressure and temperature

Koutaro Hikosaka², *Ryosuke Sinmyo^1,2, Kei Hirose^2,3, Takayuki Ishii⁴, Yasuo Ohishi⁵ (1. Meiji Uni., 2. U. Tokyo, 3. Tokyo Tech., 4. BGI, 5. JASRI)

Keywords:iron oxide, diamond-anvil cell, high pressure, Fe4O5, Fe5O6

We performed in-situ X-ray diffraction measurements in a laser-heated diamond-anvil cell to determine the phase relations in Fe₅O₆ and Fe₄O₅ bulk compositions to 61 GPa and to 2720 K. Result indicates that none of the compounds between FeO and Fe₃O₄ are formed beyond ~40 GPa at 1800 K. As some superdeep diamonds have genetic links with these high-pressure iron oxides, our results give constraints on pressure and temperature conditions of their formation.