Structural, optical, and magnetic properties of a new system of Bi(Mn0.5Ti0.5)O3-modified Bi0.5Na0.5TiO3 materials

Abstract

Bi(Mn0.5Ti0.5)O3-modified Bi0.5Na0.5TiO3 materials were fabricated via the sol-gel method. X-ray diffraction and Raman scattering studies indicated that Bi(Mn0.5Ti0.5)O3 materials were a solid solution in host Bi0.5Na0.5TiO3 materials. The optical band gap energy was reduced from 3.06 eV for pure Bi0.5Na0.5TiO3 sample to 1.78 eV for 9 mol% Bi(Mn0.5Ti0.5)O3 solid solution in Bi0.5Na0.5TiO3 samples. The magnetic properties of Bi0.5Na0.5TiO3 materials were tuned in terms of Bi(Mn0.5Ti0.5)O3 concentration. The competition of weak ferromagnetism and diamagnetism was obtained in pure Bi0.5Na0.5TiO3 materials. The diamagnetic components of pure Bi0.5Na0.5TiO3 materials were suppressed and showed typical ferromagnetism for Bi(Mn0.5Ti0.5)O3-modified host Bi0.5Na0.5TiO3 materials with 3 mol% Bi(Mn0.5Ti0.5)O3 as a solid solution. A high Bi(Mn0.5Ti0.5)O3 concentration in a solid solution in host Bi0.5Na0.5TiO3 materials was favorable to paramagnetic and antiferromagnetic-like components. The optical band gap energy and tunable magnetic properties of Bi0.5Na0.5TiO3 materials were decreased by Bi(Mn0.5Ti0.5)O3 materials as a solid solution possibly because of diffusion and random incorporation in the host lattice of Bi0.5Na0.5TiO3 materials. Our work could be used as a basis for further developing multifunction materials by integrating ferromagnetism to lead-free ferroelectric materials for smart electronic applications.