Impact of synthesis-induced disorder on the structural, electrical, and optical properties of BaTi1-xHfxO3, 0 ? x ? 0.08

Abstract

We investigated the effect of hafnium (Hf4+) substitution on the structural, morphology, electrical, and optical properties of barium titanate (BT), prepared via the modified (low-temperature sintered) solid-state reaction route. The structural refinement confirmed the formation of a single phase for pure and a mixture of phases for Hf-doped BT. The presence of [TiO6] and [HfO6] octahedra was confirmed by Raman analysis. The XPS analysis confirmed the formation of structural disordering associated with oxygen vacancies. The highest piezoelectric charge coefficient of 193 pC/N was found for BHT-5 (5% Hf). An energy storage efficiency & GE; 65% makes all the ceramics suitable for high-energy-density capacitors applications. With an increase in Hf4+ content, the optical bandgap widened. The direct optical bandgap ranged from 2.783 to 2.892 eV, making them ideal for optoelectronic applications. The presence of Ti3+/Hf3+ ions decreased the optical bandgap for all compositions.