The effect of Ni doping on the structural, optical and dielectric properties of nanocrystalline YbCrO3

Abstract

This work focuses on the detailed crystal structures and optical and dielectric properties of sol-gel derived Ni doped YbCrO3 composites. The orthorhombic crystal configuration with Pbnm space group of the as-synthesized samples was confirmed using X-ray diffraction measurements. The obtained values for the reliability factors confirm the excellent agreement between the observed and calculated patterns. The average crystallite sizes of the doped samples determined from the Scherrer equation and Williamson–Hall analysis were found to be smaller when compared to the pristine sample. Scanning electron microscopy (SEM) images reveal the slightly elongated spherical shape particles with enhanced agglomeration in the case of the doped samples. The optical band gap of the doped samples decreases, whereas the Urbach energy shows an opposite trend. Significant changes were observed in the dielectric properties and ac conductivity of the doped samples when compared to the pristine sample. The relaxation phenomenon is observed using impedance spectroscopy measurements and the shift in the relaxation peak towards higher frequencies upon increasing the Ni content suggest the lower relaxation time in the doped samples. The results indicate that the optical and dielectric properties of YbCrO3 are enhanced upon Ni doping.