Rietveld analysis, dielectric and magnetic properties of Sr and Ti codoped BiFeO3 multiferroic

Polycrystalline Bi0.8Sr0.2Fe1-xTixO3 (x = 0.0, 0.1, 0.2) multiferroics were synthesized via the conventional solid state reaction method. The structure, dielectric relaxation, and magnetic properties of as prepared samples were investigated. The crystal structure examined via XRD and Rietveld analysis confirmed a single phase rhombohedral (space group R3c no. 161) structure. In the Rietveld refinement, good agreement between the observed and calculated pattern was observed. The dielectric response of these multiferroics was analyzed in the frequency range of 10 Hz to 5 MHz at different temperatures. All the samples showed dispersion in dielectric constant (epsilon) and dielectric loss factor (tan delta) values. The temperature dependence of epsilon and tan delta showed broad peaks. A reduction in the values of epsilon and tan delta was observed upon the incorporation of Ti. Magnetic measurements were carried out at room temperature up to a field of 20 kOe. Magnetic hysteresis loops revealed a significant increase in magnetization with Ti substitution. A remnant magnetization (M-r) of 33.428 memu/g and a coercive field (H-c) of 1.724 kOe were observed in the sample with x = 0.2. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3646557]