Meeting room "Glova", 4 floor, Integrated Research Building
Abstract
Crystal structure of iron composing the Earth’s inner core has been a major controversial issue. Here we propose stacking disordered structure of iron as the candidate. First-principles calculations indicated that a stacking fault concentration reaches approximately 40% at inner core conditions. Simulated x-ray diffraction pattern of the stacking disordered iron is hardly distinguishable from that of the hexagonal close-packed (hcp) structure at low temperature, but it transforms to a mixed pattern of the hcp, face-centered cubic and double hcp structures with increasing temperature. Thus, prolonged conflicts on the stable structure of iron could be reconciled by taking into account the temperature-dependent stacking disordered iron. Moreover, the stacking disordering yields enhancement of the elastic anisotropy in hcp. These results could give new insights into the Earth’s inner core structure.
For inquiry：Taku Tsuchiya TEL:（089）927-8198
E-mail takut@sci.ehime-u.ac.jp
