Crystal structure and multiferroic properties of BiFeO3–Na0.5K0.5NbO3 solid solution ceramics prepared by Pechini method

Abstract A series of solid solution ceramics of (1 − x)BiFeO3–xNa0.5K0.5NbO3 (0.06 ≤ x ≤ 0.30) were successfully synthesized by Pechini method. The structural, magnetic and ferroelectric properties were investigated. The ceramics presented single phase perovskite structure, in which the transformation from rhombohedral to tetragonal symmetry occurred at x = 0.15. The room temperature ferromagnetism was observed in the samples of x ≤ 0.15 with rhombohedral structure, whereas the ferromagnetism disappeared as x increased. The enhanced ferroelectric property was observed, and the remnant polarization and coercive electric field could get 1.83 μC/cm2 and 11.2 kV/cm for the sample of x = 0.18. Moreover, magnetodielectric effect was investigated, revealing the coupling between the magnetic and electric orders essential for the multiferroic materials.