Investigation of morphological and dielectric properties of barium titanate with niobium

In this study, barium titanate (BaTiO₃) doped with varying concentrations of niobium (Nb) was synthesized via mechanical alloying. The precursor powders were precisely weighed and milled using a SPEX ۸۰۰۰ device, followed by compaction and sintering at ۱۵۰۰ °C. Structural and morphological characterizations were performed using FT-IR, SEM/EDS, and Zetasizer analysis. The FT-IR spectrum of the uncalcined sample revealed characteristic absorption bands for O–H vibrations, carbonate groups, and a strong Ti–O bond, confirming the formation of the titanate framework. SEM images showed agglomerated particles alongside nanoscale grains, with Zetasizer results indicating an average particle size of ۳۵ ± ۵ nm. Dielectric properties were evaluated using an LCR meter across a frequency range of ۲۰ Hz to ۱۰ MHz. Among the Nb-doped samples, the composition containing ۰.۳ wt% Nb (S-۰.۳Nb) exhibited the highest dielectric constant (~۱۷,۰۰۰ at ۲۰ Hz), suggesting optimal doping for enhanced electrical performance. Microstructural analysis of S-۰.۳Nb revealed two distinct phases with uniform Nb dispersion and spherical morphology. The slight increase in particle size compared to undoped BT was attributed to the larger ionic radius of Nb⁵⁺.