Magneto Electric coupling in the multiferroic composite 1 x Ba5RTi3V7O30 xBiFeO3

Abstract

Samples of Ba5RTi3V7O30(R= Pr, Tb), members of tungsten bronze family were prepared by high temperature Solid State Reaction Technique with AR(Analytical Reagent) grade precursors(i.e., oxides and carbonates). Preliminary X-ray analysis of the material to ensure the single phase formation are done at room temperature, X-ray diffraction patterns were taken over a wide range of Bragg s angles(10 °C lt 2and#120580; lt 80 °C ) using CuK and#120572; (and#120582;=1.5405 Å) radiation. The reflection peaks of the composite are indexed and the lattice parameters are determined by observed d values (interplanar spacing). Surface morphology was studied by Scanning electron microscope(SEM: JOEL-IT300). Dielectric characterization is done for frequency upto 1 MHz at various temperatures by Impedance Analyser(HIOKI-IM3536). Further, the solid solution of (1-x)Ba5RTi3V7O30-xBiFeO3 where R=Tb, Pr; has been synthesized by mixing the tungsten bronze ferroelectric family, Ba5RTi3V7O30 with the perovskite structured multiferroic, BiFeO3. For fabrication the Solid State Reaction technique with different x values are employed. XRD(X-ray Diffractogram) shows certain peaks of BiFeO3 are also visible in the XRD pattern of the sample with x= 0.3, 0.5, and 0.7. Thus it seems that the samples with x=0.3, 0.5, and 0.7 are composite sample in which one phase is of BiFeO3 which confirms the formation of composite phase compound. Grain morphology has been studied by Scanning electron microscope (SEM: JOEL-IT300). Surface morphology shows that average grain size increases by increasing x i.e. by increasing BiFeO 3 in the system. By Impedence Analyser (HIOKI-IM3536) dielectric properties such as dielectric constant and loss tangent has been measured in a wide temperature range (RT-500 °C) and also at wide range of frequency which confirms the Ferroelectric nature of all the samples with increasing content of BiFeO3 in these composite the dielectric constant decreases. newline