Correlation of Structure and Transport Properties of Bi2Ca2−xLaxCoO6 Nanoparticles Synthesized by Coprecipitation Method

In this work, the frequency-dependent conduction mechanism and dielectric relaxation processes in Bi₂Ca_2−xLa_xCoO_6, x = 0.00−0.15 (BCLCO), were investigated at temperatures between 100°C and 500°C. In this study, the novel BCLCO was successfully prepared by the coprecipitation process. We revealed the samples under study have a monoclinic structure by the investigation of x-ray diffraction (XRD) data. The XRD data was used to compute the crystallite size, lattice parameters, and unit cell volume. It is evident from all of the characterizations that the BCLCO was successfully prepared. Electrical and dielectric properties were examined with frequency at different temperatures. According to the analysis of electrical conductivity, the prepared samples exhibit semiconducting behavior. The dielectric constant is enhanced with temperature and decreases with frequency due to space charge polarization, which has been described by the Maxwell–Wagner relaxation model. In this investigation, the dielectric constant was examined up to a maximum value of 2.17 × 10⁶. In the studied samples, the Havriliak–Negami model was employed to calculate the spreading factor values. Jonscher’s universal power law was used to study the conduction mechanism of the synthesized samples. tan δ and dielectric constant studies confirmed the thermal hopping of charge transport in BCLCO. According to modulus spectroscopy, the examined samples indicated the existence of a temperature-dependent relaxation mechanism. The thermal conductivity (k = 0.540 W/m-K) was greatly reduced by La-doped bismuth cobaltite, which could make it appropriate for thermal barrier coating.

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