Outer core stratification by crystallization of SiO2

George R Helffrich1, Kei Hirose1, Guillaume Morard2 and Ryosuke Sinmyo1, (1)Tokyo Institute of Technology, Earth-Life Science Institute, Tokyo, Japan, (2)IMPMC Institut de Minéralogie et de Physique des Milieux Condensés, Paris Cedex 05, France