Effect of samarium substitution on dielectric and electrical properties of Sr1-xBaxBi2Ta2O9 (x = 0, 0.05) lead-free ceramics

Citric acid solution and solid state are paired to prepare Sm-doped Sr 1 − x Ba x Bi 2 Ta 2 O 9 (x = 0, 0.05) ceramics in a way that byproducts are not released. XRD technique demonstrated that the compounds maintained orthorhombic structure, whereas lattice parameters analysis showed that dopants induce distortion of the orthorhombic unit cell. SEM revealed that plate-shaped dense ceramics can be fabricated. The electrical study sheds light on the influence of motif on carrier transport in Sr 1 − x Ba x Bi 2 Ta 2 O 9 (x = 0, 0.05) ceramics. A partial Sm/Ba occupational disorder in lattice structure induces a diffuse phase transition. Compared to pure samples, the effect of samarium on dielectric properties was markedly revealed, reducing dielectric loss and enhancing the dielectric constant at room temperature. The electoral study carried out at higher temperatures, suggests that the mobility of the charge carrier is mainly due to a hopping mechanism according to the correlated barrier hopping (CBH) model fitted to hopping conduction. Through the electrical modulus model, the mobility of the charge carriers in the system is involved in a long-short-range hopping approach. Sm-dopant content leads to an upshift in the barrier energy of the AC, DC, and CBH conductivity models. Thus, when Sm atoms go up to 1.37 at% (x = 0.1) may hamper the free movement of charge carriers, leading to lower tanδ values.