STRUCTURAL TRANSITION OF LA.BA.CU.O DOPED WITH IRON

Crystal structures of LaBa2Cu3-xFexOy with 0.0 less than or equal to x less than or equal to 0.25 show an anomalous structural phase transit ion depending on Fe contents. With Fe content increasing the structure varies in the form of orthorhombic-to-tetragonal phases and then rege neration of orthorhombicity from tetragonal phase,which is observed fr om the separation or overlap of (020) and (200) lines in the X-ray dif fractograms. Variation of lattice constants a, b and c with Fe content also supports by the anomalous phase transition.