Defect-Mediated Room Temperature Ferromagnetism in Lead-Free Ferroelectric Na0.5Bi0.5TiO3 Materials

The injection of ferromagnetism properties to ferroelectric materials is a feasible strategy for integrating new functionalities to create next-generation electronic devices. In this study, Ni-doped lead-free ferroelectric Na 0.5 Bi 0.5 TiO 3 materials were synthesized using the sol-gel method. The optical band gap was reduced from 3.12 eV to 2.23 eV for un-doped and 9 mol% Ni-doped Na 0.5 Bi 0.5 TiO 3 materials, respectively, when Ni was substituted at the Ti site. The Ni-doped Na 0.5 Bi 0.5 TiO 3 materials exhibited ferromagnetism at room temperature. The maximum magnetization was found to be 0.91 μ B /Ni. Our work offers insight into the role of transition metals in room temperature ferromagnetism in lead-free ferroelectric materials for the creation of new types of green multiferroic materials.