Features of crystal structures in the correlated-electron system Sr1-xLaxTiO3

The details of crystal structures in Sr1-xLaxTiO3 with the simple perovskite structure have been investigated by means of electron diffraction at room temperature. When the Sr content decreases, the crystal structure was found to change as follows; Pm3m (x=0), R(3) over barc$ (0.05 less than or equal to x<0.6), and Pm3m (0.6<x less than or equal to 1.0). That is, the Pbnm structure results from the condensation of both M3 and R25 modes in the Pm3m structure, which are rotation modes of the TiO6 octahedron, while only the R25 displacement is involved in the R(3) over barc$ structure.