Research Projects

The development of energy storage devices with high density and efficiency is crucial due to the scarcity of natural energy resources like oil, fossils, coal, and gas. Dielectric capacitors have gained attention due to their high power density, fast charging/discharging rate, and long cycling life times. Pb-free AgNbO₃ (AN) is a promising candidate due to its antiferroelectric (AFE) double hysteresis loop and high polarization properties under an electric field. However, the dielectric constant and energy density in AN are still low, making it difficult to realize in energy device applications. Several structural studies have been conducted on AN, but room temperature structural features remain ambiguous. The ferroelectric (FE) properties are studied using an electric field, while X-ray diffraction (XRD) patterns are collected without. There are also few reports on theoretical calculations to understand instabilities caused by the introduction of elements at A and/or B-sites. To improve the energy storage density function of AN, chemical modification is widely accepted. In situ X-Ray studies are suggested to study structural changes from AFE to FE state. Local structural and density functional theory (DFT) studies on modified AN samples will help understand microscopic insights affecting FE/AFE orderings and improve energy density properties. This proposal aims to investigate structural, local structure, FE, dielectric, and density function theory studies to analyze and improve energy density properties of AN by substituting suitable rare earth elements at Ag-site and/or transition metal elements at Nb-site.