title: Impact of Fe on structural modification and room temperature magnetic ordering in BaTiO3.
abstract: Ba1-xFexTiO3(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 BaTiO3whereas 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-1mode. 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-1and 650cm-1are 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 BaTiO3lattice has been decided using EPR Spectra precisely. Room temperature magnetic ordering is observed in Fe substituted BaTiO3using PPMS. The coexistence of ferroelectric and magnetic ordering is established in the present study for optimized Fe substituted BaTiO3.
authors.affiliation: Magnetism and Magnetic Materials Laboratory, Department of Physics, Pondicherry University, Pondicherry 605014, India.
authors.forename: Soumya
authors.initials: S
authors.lastname: Rajan
authors.affiliation: Magnetism and Magnetic Materials Laboratory, Department of Physics, Pondicherry University, Pondicherry 605014, India.
authors.forename: P M Mohammed
authors.initials: PMM
authors.lastname: Gazzali
authors.affiliation: Magnetism and Magnetic Materials Laboratory, Department of Physics, Pondicherry University, Pondicherry 605014, India. Electronic address: chandgc@gmail.com.
authors.forename: G
authors.initials: G
authors.lastname: Chandrasekaran
keywords: Room temperature magnetic ordering; Temperature dependent Raman and Impedance spectroscopy; XPS spectra