Crystal structure, dielectric and magnetic properties of (1 − x )BaTiO 3 -( x )BaFe 12 O 19 ( x = 0.50, 0.60, 0.70) multiferroic composites

Multiferroic composites having composition (1 − x ) BaTiO 3 –( x ) BaFe 12 O 19 ( x = 0.50, 0.60, 0.70) were synthesized by the conventional solid-state reaction method. These composites constitute BaTiO 3 as the ferroelectric phase and BaFe 12 O 19 as the ferromagnetic phase. X-ray diffraction (XRD) was used to analyze the formation of crystal structure and phase purity. The formation of individual phases took place without evolving any chemical reaction in all the prepared samples, which evidences the good synthesis of composite ceramics. The presence of characteristic symmetry consisting of tetragonal (P4mm) and hexagonal (P63/mmc) was confirmed by the Rietveld refinement of XRD data. The effect of alternate concentration variation of the component ceramics has been analyzed over the dielectric, electric, and magnetic properties of the composites prepared. The dielectric constant ( ε ') and dielectric loss (tan δ ) were recorded in the frequency and temperature domain and these have been observed to follow Maxwell Wagner’s dispersive behaviour. The dielectric relaxation and conduction mechanism were analyzed with the help of complex impedance spectroscopy (CIS). In Nyquist plots, two semi-circles, whose centres lie below the real axis, were observed for all the prepared samples. Magnetization (M) versus magnetic field (H) loops, recorded at room temperature shows, gradual increase with the increase in ferrite content. These hysteresis loops were fitted by the law of approach to saturation (LAS) and values of various magnetic parameters were evaluated. The gradual enhancement in the values of magnetic parameters may be attributed to an increase in the ferromagnetic phase component.