Room-temperature ferromagnetism in Fe-based perovskite solid solution in lead-free ferroelectric Bi 0.5 Na 0.5 TiO 3 materials

Abstract The integration of ferromagnetism in lead-free ferroelectric materials is important to fabricate smart materials for electronic devices. In this work, (1 −  x )Bi 0.5 Na 0.5 TiO 3  +  x MgFeO 3- δ materials ( x  = 0–9 mol%) were prepared through sol–gel method. X-ray diffraction characterization indicated that MgFeO 3- δ materials existed as a well solid solution in lead-free ferroelectric Bi 0.5 Na 0.5 TiO 3 materials. The rhombohedral structure of Bi 0.5 Na 0.5 TiO 3 materials was distorted due to the random distribution of Mg and Fe cations into the host lattice. The reduced optical band gap and the induced room-temperature ferromagnetism were due to the spin splitting of transition metal substitution at the B -site of perovskite Bi 0.5 Na 0.5 TiO 3 and the modification by A -site co-substitution. This work elucidates the role of secondary phase as solid solution in Bi 0.5 Na 0.5 TiO 3 material for development of lead-free multiferroelectric materials.