Investigation of variable range hopping and dielectric relaxation in GdCrO3 orthochromite perovskites

Abstract

This study investigates the structural, electrical, and dielectric properties of GdCrO₃ (GCO) compounds. X-ray diffraction analysis confirmed the formation of the perovskite phase of GCO, crystallizing with the Pbnm space group. Scanning electron microscopy (SEM) was employed to examine the morphology and chemical composition of the powder, ensuring compound homogeneity, while transmission electron microscopy (TEM) provided insights into the internal structure and finer morphology of the GCO sample. Electrical measurements revealed that GCO exhibits semiconductor behavior, with a notable increase in conductivity as temperature rises, attributed to enhanced charge carrier mobility and hopping conduction mechanisms. Dielectric analysis demonstrated significant frequency-dependent behavior, characterized by various polarization effects and relaxation phenomena. GCO is a promising material for energy storage due to its giant permittivity and low energy loss. The activation energies derived from the electrical and dielectric measurements indicate higher resistance within the grains compared to the grain boundaries, suggesting complex conduction processes. Additionally, the dielectric loss spectra revealed substantial losses, likely due to defect states such as oxygen vacancies and mixed valence states, indicating a highly disordered material. These comprehensive insights into the structural and functional properties of GCO highlight its potential applications in electronic and electrical devices where controlled conductivity and dielectric properties are crucial.