Effect of Ce3+ ion substitution on the structural, optical, electrical and ferroelectric properties of NdFeO3 nanoparticles

Nanocrystalline Nd1 - xCexFeO3 samples (where, x = 0.00, 0.03, 0.05, & 0.07) were synthesized through the sol-gel citrate method to explore their structural, optical, electrical, and ferroelectric properties. Analysis of X-ray diffraction (XRD) data allows for the determination of phase purity and crystallinity. The data obtained from XRD pattern, along with Rietveld refinement, reveals an orthorhombic structure with the space group Pbnm. For every sample, the unit cell characteristics, such as bond lengths and bond angles are determined. The application of the Scherrer equation reveals that the calculated crystallite size falls within the range of 12-15 nm. The distinctive bands observed in FTIR spectra serve as additional confirmation of the desired sample formation. From the absorption study of the synthesized powder samples, the optical band gap comes out to be within the range of 2.68-2.84 eV. SEM images depict grains of diverse size with well-defined grain boundaries and irregular shapes. Elemental composition, verified through EDX spectra, reveals the absence of impurity elements. Adding a small amount of Cerium (Ce) to NdFeO3 creates a promising material for various applications. This is because Cerium reduces the material's ability to store electrical energy (lowers dielectric constant) without significantly increasing energy loss (keeps dielectric loss low, tan delta less than 1). The Jonscher power law is applied to model AC conductivity data indicating a non-ideal Debye relaxation process. DC electrical resistivity data are fitted by using small polaron hopping (SPH) and variable range hopping (VRH) model. Plots demonstrate the metal-semiconductor behaviour above room temperature of Ce-doped NdFeO3 samples. The PE loops highlight the ferroelectric properties of the material.