Improved Dielectric, Magnetic, and Multiferroic Properties of (Bi_0.5Na_0.5)_0.7La_0.3(Ti_0.7Fe_0.3)O₃Ceramics Synthesis by the Solid‐State Combustion Technique

Abstract

Lead‐free (Bi0.5Na0.5)0.7La0.3(Ti0.7Fe0.3)O3 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 °C for 2 h and sintered between at 800 and 900 °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 °C for 2 h and the crystal size increases from 47 to 62 nm when the calcination temperature increases from 700 to 800 °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 (εr ≈ 589 and tanδ ≈ 0.572), soft ferroelectric behavior, and excellent magnetic properties (Ms ≈ 0.091 emu g−1, Mr ≈ 0.0026 emu g−1) is obtained from the ceramic sintered at 875 °C for 2 h. The multiferroic BNLTF ceramic sintered at 875 °C has a maximum magnetoelectric coupling coefficient (αE ≈ 2.08 mV cm−1 Oe−1) when the magnetic field is near 4500 Oe.