Electric and magnetic properties of multiferroic CZFMO doped BNLTBKTBaT composite ceramics prepared via the solid-state combustion method

The present research work describes in detail investigations of the multiferroic properties of (1-x) (0.85Bi0.5Na0.475Li0.025TiO3-0.11Bi0.5K0.5TiO3-0.04BaTiO3)-xCo0.6Zn0.4Fe1.7Mn0.3O4 [(1-x)BNLTBKTBaT-xCZFMO]; x = 0, 0.05, 0.10, 0.15 and 0.20 composite ceramics, synthesized by the solid-state combustion technique. The effect of increasing x content on the phase structure, microstructure, electrical and magnetic properties of (1-x)BNLTBKTBaT-xCZFMO composite ceramics was investigated. X-ray diffraction patterns of the BNLTBKTBaT sample showed a pure perovskite phase (rhombohedral and tetragonal structures). When CZFMO was added, the XRD patterns showed a co-structure between perovskite and cubic spinel ferrite structures. The composite grains were composed of large and small sizes, which were composed of mainly the elements of BNLTBKTBaT and CZFMO, respectively. As x increased, the average grain size of the larger grains increased, and the smaller grains got smaller. The density decreased from 5.54 to 4.61 g/cm³ as x increased. Increasing the amount of CZFMO in BNLTBKTBaT also resulted in a decrease in the dielectric constant (εr) and the remnant polarization (Pr), with the leakage current observed at x = 0.20. The saturation magnetization (Ms) and the magnetoelectric coupling coefficient (αE) increased with increased x. It was found that x = 0.15 gave the optimal electric, magnetic, and magnetoelectric properties (εr = 425, Pr = 1.64 μC/cm, Ms = 1.1948 emu/g and αE = 4.88 mV/cm-Oe), which makes the composite potentially more applicable for information technology and spintronics devices.