Synthesis of (1-x)bife0.9La0.1O3+x(Ni0.6Zn0.4Fe0.94V0.06O4) Nanostructured Multiferroic Composites and Study of its Structural, Magnetic and Electrical Properties

Abstract

The multiferroic composites (1-x) BiFe0.9La0.1O3+ x (Ni0.6Zn0.4Fe0.94V0.06O4) are made with the combination of perovskite and ferrite materials. The nanoparticles are synthesized by using solid state reaction method and some mechanical dispersion techniques like magnetic stirring, ultrasonification and centrifugation. X-ray diffraction method with Rietveld refinement was established to see multiphase formation that consists with perovskite and ferrite compositions. From Rietveld analysis, rhombohedral to orthorhombic phase transition was found up to x = 0.7 and the pure cubic ferrite structure was found for x = 1 content. At x = 0, the sample is in rhombohedral and orthorhombic mixed phases but with the increasing in x (as ferrite content) the cubic phase was visible. At fully ferrite contents where x = 1, there has no rhombohedral and orthorhombic phase has been visible but only cubic phase is formed. The goodness of fitting confirmed that the composites are made with well distribution of perovskite and ferrite materials. The results from Rietveld analysis show that the increasing Ni0.6Zn0.4Fe0.94V0.06O4 (NZVFO) contents the ferrite phase fraction was increased whereas the perovskite phase fraction decreased. The Field emission scanning electron microscopy (FESEM) has been used to understand the surface morphology of composites. The proportion and contribution of particles inside the composites have been found by EDX analysis. Initially, all prepared samples were heated at 150oC and the nanostructure was confirmed by FEESEM photograph where the size of particles were about 20 ~ 30 nm and after increasing annealing temperature, increase in grain size is clearly observed. At 300oC, 450oC, 600oC and 850oC annealing temperatures the grain sizes are in between 30~40 nm, 50~80 nm, 160 ~ 260 nm and 800 ~ 1700 nm respectively. The magnetization, saturation magnetization and coercivity has calculated by using Vibration sample magnetometer (VSM), where magnetization is lowest for pure BiFe0.9La0.1O3 (BLFO) perovskite phase and increased with increasing NZVFO ferrite contents. The magnetization is maximum for x = 1 which may be contributed by total of ferrimagnetic contents. The temperature dependent magnetization was taken at 5Oe constant field for both of heating and cooling mechanism where the Curie temperatures have Curie temperatures are 364oC and 350oC for pure perovskite mixed phases (x = 0) and cubic ferrite phase (x = 1) respectively. The frequency dependent dielectric constant is maximum for Bismuth perovskite content but it was lower as ferrite contents increased. On the other hand resistivity increased with increasing ferrite content. Frequency dependent permeability was maximum for pure NZVFO content but in BLFO content, permeability became low.