Synchrotron x-ray diffraction reexamination of the sequence of high-temperature phases inSrRuO3

Abstract

The crystal structure of ${\mathrm{SrRuO}}_3$ at high temperatures has been studied at fine temperature intervals using high-resolution synchrotron diffraction. It has been shown that ${\mathrm{SrRuO}}_3,$ orthorhombic in space group Pnma, at room temperature, changes by a continuous transition to a structure in Imma at about 685 K, then by a discontinuous transformation to tetragonal $I4/mcm$ at about 825 K, and finally, continuously, to cubic at near 950 K.