Dielectric and magnetic studies of (NKNLS)1−x–(NZFO)x multiferroic composites

• Samples of perovskite (NKNLS)1−x–(NZFO)x were prepared by the conventional solid-state reaction method.
• XRD indicated that the NKNLSNZFO phases retain their tetragonal and spinel structure.
• SEM figures shows rectangular regions of a chain of self-connected NZFO grains distributed in the matrix of NKNLS phase.
• TcFE is observed to decrease with the increase in the mole percentage of NZFO.

Polycrystalline samples of perovskite Na0.5K0.5[0.95(Li)0.05(Sb)0.05(Nb)0.95O3] (NKNLS)1−x–[Ni0.5Zn0.5Fe2O4] (NZFO)x were prepared by the conventional solid-state reaction method. X-ray powder patterns indicated that the NKNLSNZFO phases retain their tetragonal and spinel structure in composites. There are no structural changes observed for both the phases in the composites. SEM figures show rectangular regions of a chain of self-connected NZFO grains distributed in the matrix of NKNLS phase, indicating 3–1-type connectivity. In the same composite, 3–3-type connectivity is also observed. The dielectric transition temperature of x = 0.20 is close to the ferroelectric transition temperature (TcFE) for pure NKNLS. For composites TcFE is observed to decrease with the increase in the mole percentage of NZFO. From magnetic measurement we observed that for each sample both measurements (ZFC and FC) show separate M(T) curves overlapping at the highest temperature. This behavior probably arises from the magnetic domain with different sizes.