Empirical Investigation of the Dielectric and Ferroelectric Properties of Barium Titanate Ceramics Doped with Nigerian Mineral Additives

Barium titanate is the archetypal ferroelectric perovskite ceramic widely used in capacitors, piezoelectric transducers, and electro-optic devices. Modification of its dielectric and ferroelectric properties through controlled doping offers pathways to enhanced device performance and temperature stability. This study empirically investigates the effect of doping barium titanate with low-concentration additions of ilmenite and rutile mineral powders sourced from beach sand deposits in Ondo State, South West Nigeria, as locally available sources of titanium and iron oxide dopants. Ceramic samples were prepared by the conventional solid-state reaction method at sintering temperatures of 1250, 1300, and 1350 degrees Celsius with dopant concentrations of 0.5, 1, 2, and 4 mol percent. Phase composition was analyzed by X-ray diffraction, and microstructural development was characterized by scanning electron microscopy. Dielectric constant, loss tangent, and remnant polarization were measured as functions of temperature from 20 to 200 degrees Celsius using an LCR impedance analyzer and a Sawyer-Tower hysteresis loop circuit. Doping with ilmenite at 1 mol percent was found to broaden and flatten the dielectric constant-temperature peak near the Curie transition at 120 degrees Celsius, a behavior useful for capacitor applications requiring temperature-stable permittivity. The study fills a gap in literature on locally sourced mineral dopant effects on functional ceramic properties and provides composition-processing maps for optimized dielectric performance. Keywords: barium titanate, ferroelectric, dielectric properties, mineral dopants, Ondo State