Effect of Surface Moisture on Dielectric Behavior of Ultrafine BaTiO ₃ Particulates

Abstract

The effects of adsorbed H 2 O on the dielectric properties of ultrafine BaTiO 3 particulates of varying particle size and environmental history were determined. The dielectric behavior depends strongly on surface hydration. No particle size dependence of dielectric constant was found for dehydroxylated surfaces in ultrafine particulate (unsintered) BaTiO 3 materials. For equivalent particle sizes, the ac conductivity is sensitive to surface morphology. Reactions with H 2 O vapor appear to account for the variations in dielectric properties. Surface dehydration was effectively accomplished by washing as‐received powders in isopropanol.