LAUSR

The polycrystalline samples of Bi 0.9− x Sm 0.1 Gd x FeO 3 (BSFO) perovskites system, modified with the Gd substitution (0.0 ≤  x  ≤ 0.1), were prepared using a solid-state ceramic route. In the present work, the effect of A-site double substitution (Sm and Gd) on Polomska transition before and after solid solubility limit is studied using high-temperature dielectric and conductivity measurements. The X-ray diffraction studies suggest the phase transformation from pure rhombohedral into pseudocubic up to x  ≤ 0.05. The lattice parameters are observed to decrease for x  ≤ 0.05. After x  > 0.05, secondary phases start appearing due to attaining the solubility limit of BiFeO 3 . The SEM study reveals that the grains are of hexagonal shape and grain sizes are obtained in the range of ∼ 1.9–2.5 µm. The remanent magnetization has observed to increase linearly with the concentration of Gd substitution in BSFO. In the temperature range 80 to 300 °C, the Bi 0.825 Sm 0.1 Gd 0.075 FeO 3 sample (i.e., x  = 0.075) follows Arrhenius behavior with almost single slope with significantly enhanced conductivity. This shows that double substitution has suppressed the dielectric anomalies of bismuth ferrite.