Impact of Fe on structural modification and room temperature magnetic ordering in BaTiO 3 .

Ba1-x Fex TiO3 (x=0, 0.005, 0.01) polycrystalline ceramics are prepared using solid state reaction method. Structural studies through XRD, Raman and XPS confirm single tetragonal phase for BaTiO3 whereas a structural disorder tends to intervene with the introduction of smaller Fe ions which reduces the tolerance factor and tetragonality ratio. Grain size of the samples is estimated using SEM micrographs with ImageJ software and chemical composition is confirmed using EDX spectra. Raman spectra measured in the temperature range of 303K to 573K showers light on the structural phase transition exploiting a significant disappearance of the 306cm-1 mode. Further, structural analyses suggest the entry of Fe into the B-site upon increasing its concentration in BaTiO3 . The dopant sensitive modes lying at around 640cm-1 and 650cm-1 are assigned to lattice strain. A reduction in ferroelectric to paraelectric transition temperature is observed with a transformation from diffused type to normal ferroelectric upon the increased Fe content. The oxidation state of Fe in the BaTiO3 lattice has been decided using EPR Spectra precisely. Room temperature magnetic ordering is observed in Fe substituted BaTiO3 using PPMS. The coexistence of ferroelectric and magnetic ordering is established in the present study for optimized Fe substituted BaTiO3 .