The Modified Magnetodielectric Response In Knn-Czfmo Based Particulate Multiferroic Composite System

Lead-free multiferroic composites of 1-x(K0.5Na0.5NbO3-x(Co0.6Zn0.4)(Fe1.7Mn0.3)O-4 (KNN-CZFMO), where x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5 and 1.0, have been investigated for their structural, morphological, electrical, magnetic, dielectric and magneto-dielectric properties. Presence of KNN and CZFMO crystal structure in each composite has been confirmed from X-ray diffraction analysis (XRD). Cuboidal-shaped grains of KNN and spherical-shaped grains of CZFMO have been observed by scanning electron microscopy (SEM). The room temperature ferroelectric behavior as confirmed by polarization versus electric field (P-E) hysteresis loops has been found to be decreasing with increasing CZFMO concentration. Increasing magnetic ordering with the increase in CZFMO concentration in the prepared composites has been observed by magnetization versus magnetic field (M-H) hysteresis loops. The electrical conductivity of composites has been studied using Jonscher's universal power law. The room-temperature dielectric constant (epsilon ') and dielectric loss (tan delta) have been observed to decrease with the increase in the frequency of the applied external electric field. The dielectric relaxation behavior has been observed using curve fitting analysis via the Havriliak-Negami relaxation model. Maximum value of the magnetodielectric (MD) effect similar to -11% at a frequency of 1 kHz with the applied magnetic field of 1 T has been achieved for 0.9 KNN-0.1 CZFMO (x = 0.1) composite in the present research work.