Sound velocity measurements of ε–FeOOH up to 24 GPa

The sound velocity and density of ε–FeOOH have been simultaneously measured up to 24 GPa at room temperature using an ultrasonic pulse–echo–overlap method and a Kawai–type multi–anvil apparatus at BL04B1 in SPring–8. In the experimental pressure range, the velocity of both the P– and S–waves of ε–FeOOH was ~ 15% lower than that of an isostructural phase δ–AlOOH. The pressure dependence of the determined adiabatic bulk modulus (KS) increased in...