Improved Dielectric, Magnetic, and Multiferroic Properties of (Bi0.5Na0.5)0.7La0.3(Ti0.7Fe0.3)O3 Ceramics Synthesis by the Solid-State Combustion Technique

Lead-free (Bi0.5Na0.5)(0.7)La-0.3(Ti0.7Fe0.3)O-3 ceramics (abbreviated as BNLTF) are synthesized by the solid-state combustion technique using glycine as fuel. The effect of the firing temperature (calcined between 700 and 800 degrees C for 2 h and sintered between at 800 and 900 degrees C for 2 h) on the phase structure, microstructure, electrical, and magnetic properties is investigated. Pure BNLTF powders are obtained with a calcination temperature of 750 degrees C for 2 h and the crystal size increases from 47 to 62 nm when the calcination temperature increases from 700 to 800 degrees C. All sintered BNLTF ceramics show a pure perovskite structure with a rhombohedral phase. The average grain size increases with increasing sintering temperatures. A well-packed microstructure with the highest density (5.98 g cm(-3)), good dielectric properties at room temperature (epsilon(r) approximate to 589 and tan delta approximate to 0.572), soft ferroelectric behavior, and excellent magnetic properties (M-s approximate to 0.091 emu g(-1), M-r approximate to 0.0026 emu g(-1)) is obtained from the ceramic sintered at 875 degrees C for 2 h. The multiferroic BNLTF ceramic sintered at 875 degrees C has a maximum magnetoelectric coupling coefficient (alpha(E) approximate to 2.08 mV cm(-1) Oe(-1)) when the magnetic field is near 4500 Oe.