Low Frequency Magnetoelectric Effect in Bi0.5Na0.5TiO3–Ni0.5Zn0.5Fe2O4 Particulate Composites

We report structural, dielectric, ferroelectric, magnetic, and low frequency magnetoelectric ( ME ) properties of (1− x ) Bi 0.5 Na 0.5 TiO 3 (BNT)– x Ni 0.5 Zn 0.5 Fe 2 O 4 (NZFO) (x = 0.05–0.30) microwave sintered particulate composites. Distinct phases of BNT and NZFO were confirmed by X-ray diffraction and scanning electron microscopy. Raman spectroscopy measurement showed the absence of micro-strains within the composite. The temperature dependent dielectric studies revealed the ferroelectric to anti-ferroelectric transition at 220 °C and anti-ferroelectric to paraelectric transition at 320 °C. The ac conductivity showed both frequency dependent and independent behavior. Temperature dependent dc conductivity showed that upto 200 °C charge conduction is due to hopping of electrons, whereas at higher temperature diffusion of oxygen vacancies are responsible for the conduction. Ferroelectric and leakage current density measurements showed enhanced conduction losses with NZFO content. The maximum ME coefficient at 10 Hz frequency is obtained for 0.80BNT–0.20NZFO (4.33 mV/cm.Oe at 800 Oe). Graphical abstract