Design and characterization of a new (1-x)Na1/2Bi1/2TiO3+xBi(Ti1/2Fe1/2)O3 solid solution

Abstract A new solid solution, (1-x)Na1/2Bi1/2TiO3+xBi(Ti1/2Fe1/2)O3, was fabricated via the sol-gel method. X-ray diffraction spectroscopy revealed that the structures of Bi(Ti1/2Fe1/2)O3-modified Na1/2Bi1/2TiO3 compounds exhibited the rhombohedral symmetry of Bi1/2Na1/2TiO3. Optical band gap values decreased from 3.06 eV for pure Na1/2Bi1/2TiO3 materials to 2.51 eV for 9 mol.% Bi(Ti1/2Fe1/2)O3-modified Na1/2Bi1/2TiO3 samples. The magnetic properties of Bi1/2Na1/2TiO3 materials were tuned by controlling the amount of Bi(Ti1/2Fe1/2)O3 as solid solution. The weak-ferromagnetism and diamagnetism of pure Na1/2Bi1/2TiO3 materials changed into ferromagnetism and ended with ferromagnetism versus paramagnetism and/or antiferromagnetism-like as the concentration of Bi(Ti1/2Fe1/2)O3 increased to 9 mol.%. We provided that our work will contribute to the integration of ferromagnetism at room temperature in current lead-free ferroelectric compounds for application in smart electronic devices.