The Structure of Iron in Earth’s Inner Core

• DOI: 10.1126/science.1194662
• Publication Date: 2010-10-14T18:24:02Z
• Authors: Shigehiko Tateno; Kei Hirose; Yasuo Ohishi; Yoshiyuki Tatsumi
• Keywords: Outer core

Earth's solid inner core is mainly composed of iron (Fe). Because the relevant ultrahigh pressure and temperature conditions are difficult to produce experimentally, preferred crystal structure Fe at remains uncertain. Static compression experiments showed that hexagonal close-packed (hcp) stable up 377 gigapascals 5700 kelvin, corresponding conditions. The observed weak dependence c/a axial ratio suggests hcp elastically anisotropic temperatures. Preferred orientation phase may explain previously seismic anisotropy.