Approximately one half of the earth is believed to be MgSiO3-perovskite. The idealized crystal structure of this material consists of 8 silicon octahedra, each sitting at the corner of a cube with Mg in the center of cube. This material, examined at room pressure and temperature is slightly distorted, with small rotations of these octahedra about various axes to yield an orthorhombic crystal symmetry. Such distortions in other perovskites, however, have lead to an array of physical properties and temperature dependences of these properties which drastically differ from those expected in the absence of these rotational degrees of freedom. It is the aim of this project to investigate some of these properties with the hope of gaining insight to the behavior of MgSiO3 in the earth's lower mantle. The PI will obtain several materials with the perovskite structure to determine properties inherent to the structure and prepare samples for Brillouin spectroscopy and X-ray studies through phase transitions.
