Titanium metal at high pressure:: Synchrotron experiments and ab initio calculations -: art. no. 184102

The high pressure behavior of titanium metal is investigated experimentally using angle dispersive synchrotron x-ray diffraction as well as theoretically using ab initio electronic structure methods. Our calculations predict a direct omega to bcc transformation around 80 GPa without any intermediate crystal phases. The beta(') (bcc-structure) Ti phase was experimentally observed to coexist with the omega phase at pressures between 40 and 80 GPa on compression at ambient temperature. High-temperature treatment at 80 GPa results in a formation of a new eta phase with a monoclinically distorted bcc structure. On decompression the eta phase transforms to the pure beta(') phase.