Enhancing room-temperature ferromagnetism in Bi0.5Na0.5TiO3 via FeTiO3 solid solution

A solid solution of FeTiO 3 in host Bi 0.5 Na 0.5 TiO 3 materials was fabricated by sol–gel method. The X-ray diffraction and Raman scattering analyses indicated that the Fe cations were randomly incorporated into the host lattice of Bi 0.5 Na 0.5 TiO 3 materials, thereby resulting in the distortion of the crystal structural. The absorbance spectra of FeTiO 3 -modified Bi 0.5 Na 0.5 TiO 3 samples revealed that the optical band gap decreased from 3.11 eV for pure Bi 0.5 Na 0.5 TiO 3 materials to 2.41 eV with the addition of increasing amounts of FeTiO 3 solid solution into the host Bi 0.5 Na 0.5 TiO 3 materials (up to 9 mol% FeTiO 3 ). The tunable magnetic properties of host Bi 0.5 Na 0.5 TiO 3 materials were obtained as the concentration of FeTiO 3 as solid solution was controlled. The weak ferromagnetism as compensation of diamagnetism of pure Bi 0.5 Na 0.5 TiO 3 materials at room temperature was changed to ferromagnetism and end-off ferromagnetism combine with paramagnetism and/or antiferromagnetism with increasing FeTiO 3 concentration during the formation of a solid solution. This work proposed an alternative method for obtaining ferromagnetism at room temperature for lead-free ferroelectric materials.