Microstructural, Optical, and Magnetic Properties of BiCoO 3 -Modified Bi 0.5 K 0.5 TiO 3

Pb-free ferroelectric solid solution of Bi0.5K0.5TiO3 with BiCoO3 has been fabricated using a sol-gel technique, exhibiting room-temperature ferromagnetism. The optical bandgap of Bi0.5K0.5TiO3 reduced from 3.21 eV to 1.77 eV with increasing amount of BiCoO3 solid solution. The room-temperature ferromagnetism and bandgap reduction occurred due to BiCoO3 diffusion into Bi0.5K0.5TiO3, resulting in formation of solid solution. These results provide a simple approach to realize room-temperature ferromagnetism in Pb-free ferroelectric materials.