Photo: AFPLondon: Scientists have discovered why the crystallised iron core of the Earth remains solid, despite being hotter than the surface of the Sun. Spinning within Earth’s molten core is a crystal ball—actually a mass formation of almost pure crystallised iron—nearly the size of the moon. However at extremely high pressure the crystalline structures transform into 12-point hexagonal forms, or a close packed (HCP) phase. At low temperature BCC is unstable and crystalline planes slide out of the ideal BCC structure. “The instability kills the BCC phase at low temperature, but makes the BCC phase stable at high temperature,” he added.

Source: Mint February 19, 2017 08:38 UTC