Self-biased large magnetoelectric coupling in co-sintered Bi_0.5Na_0.5TiO₃ based piezoelectric and CoFe₂O₄ based magnetostrictive bilayered composite

In this work, magnetoelectric properties of a co-sintered bilayered composite of non-lead based piezoelectric 0.97(Bi_0.5Na_0.5TiO₃)–0.03(K_0.47Na_0.47Li_0.06Nb_0.74Sb_0.06Ta_0.2O₃) and magnetostrictive Co_0.6Zn_0.4Fe_1.7Mn_0.3O₄ are presented. Similar optimal sintering conditions of the individual components lead to a very clean interface as evidenced in the scanning electron microscopy, angle dispersive X-ray diffraction, and energy-dispersive X-ray (EDX) results. Clean interface results in strong intimate mechanical coupling between both components and causes a maximum transfer of induced strain, leading to a large magnetoelectric coupling ∼142 mV/cm·Oe measured in longitudinally magnetized-transversely polarized configuration (L-T mode). Remnant polarization ∼32 μC/cm², remnant magnetization ∼0.50 emu/g, and sufficiently high self biased magnetoelectricity ∼135 mV/cm Oe (L-T mode) were observed for this composite