Temperature-dependent dielectric relaxations and transport properties of Sm3+ & La3+ doped Bi-oxide nanoparticles

Abstract

The suggested novel rare-earth doped bismuth calcium cobaltites Bi₂Ca_2−2xSm_xLa_xCoO₆ (x = 0.000–0.075) were synthesized by a co-precipitation route. XRD was utilized for structural information. SEM and EDX were used for microstructural and elemental analysis. AC conductivities (σ_ac) were measured at temperatures of 100–500 °C. The σ_ac of all synthesized samples increased as the temperature increased, indicating that they are semi-conductive. The conduction process of all the synthesized samples was examined using Jonscher's power law. The spreading factor and relaxation time of all the synthesized samples were studied using nonlinear Debye fitting. At a high temperature of 500 °C, the dielectric curve showed anomalous behaviour that was related to the negative values of the dielectric constant at 500 kHz–3 MHz. The studied (Sm–La)-doped samples showed higher values of the dielectric constant (1.03 × 10⁸). The Cole–Cole plot used in the impedance investigation reveals that as the temperature rises, the diameter of the arcs decreases, implying a drop in impedance and rises in conductivity. The growing trend of DC electrical conductivity with temperature depicts the semi-conductive nature of the synthesized materials.