High-Pressure, High-Temperature Studies of Phase Transitions in SrOsO─Discovery of a Post-Perovskite.

Using a recently developed method for in situ high-pressure, laser heating experiments in diamond anvil cells, we obtained a novel post-perovskite phase of SrOsO. The phase transition from perovskite SrOsO was induced at 44 GPa and 1350 K in a diamond anvil cell and characterized with synchrotron powder X-ray diffraction. The newly obtained post-perovskite is quenchable and Le Bail refinements under ambient conditions yielded the unit cell parameters: = 3.