Abstract
The high-pressure Raman spectra of have been measured up to and provided unambiguous evidence of a phase transition from its ambient-pressure rutile to the -type orthorhombic structure at a pressure . Both macro- and micro-Raman spectra have been independently obtained at high pressures leading to the same conclusion about the high-pressure phase and the . The transition appears to be closely associated with the Raman-active soft mode of the rutile structure, implying that undergoes a second-order ferroelastic phase transition.
- Received 26 April 2005
DOI:https://doi.org/10.1103/PhysRevB.72.144108
©2005 American Physical Society