Determination of dual magnetic phases and the study of structural, dielectric, electrical, surface morphological, optical properties of Ce3+ substituted hexagonal ferrites

The current research project was designed to investigate the influence of Ce3+ substitution on different properties of β-type hexagonal ferrite KCexFe11−xO17 (x = 0, 0.02, 0.06 and 0.1) and to verify the experimental obtained results through theoretical calculations/modeling by performing the curve fittings. For this purpose, the sol-gel auto-combustion route was adopted to synthesize the samples. The X-rays diffraction (XRD) analysis divulged the formation of single phase structure for all samples. It was observed that the structural parameters such as lattice constants a (Å) and c (Å), dislocation density (g/cm3), crystalline size (nm) and unit cell volume V (Å)3 varied with Ce3+ concentration. Moreover, the results obtained from Williamson Hall (W-H) technique revealed that both the pure and Ce-substituted samples exhibited the positive tensile micro strain. The formation of single phase hexaferrite was also confirmed by Fourier transform infrared (FTIR) spectra. The dielectric constant, dielectric loss and tangent losses have large values at low frequency region and declined with increase in frequency. The ac conductivity revealed the increasing trend with enhancement in frequency. The Cole-Cole plot specified the influence of both grains and grain boundaries for the capacitive and resistive nature of the material. The P-E (Polarization vs electric field) loops indicated the increase of resistive nature of sample with Ce3+ contents. The DC electrical resistivity of the sample at voltage range (−200 to 0 V) was found to be diminished with substitution of Ce3+ content. The M-H loops for all the samples represented the alteration in saturation magnetization (Ms) and coercivity (Hc) with the substitution of Ce3+ contents. Consequently, the M-H loop of one concentration surprisingly exhibited both the ferromagnetic and diamagnetic behavior simultaneously.