Effect of mixing Ce3+ and Nd3+ ions in equimolar ratio on structural, optical and dielectric properties on pure cerium orthovanadate and neodymium orthovanadate

Cerium orthovanadate, neodymium orthovanadate and mixed cerium neodymium orthovanadate nanoparticles was prepared by co-precipitation method. Powder X-ray diffraction reveals tetragonal zircon structure. Slight increase in lattice parameter, volume and,decrease in X-ray density inferred that Ce3+ and Nd3+ ion replaces each other. Transmission electron-microscopy suggests change in morphology with the effect of mixing and validates formation of nanocrystalline material. The infrared transmittance spectrum confirmed, the presence of various functional groups. Dielectric properties as function of frequency show dielectric constant and loss tangent decreases with increase in frequency which is due to Maxwell-Wagner type interfacial polarization. The variation of AC conductivity measurement with frequency suggests conduction mechanism due to large polaron hopping in CeV whereas small polaron in mixed CeNdV. The activation energy decreases with rising frequency indicates the conduction mechanism is based on polaron hopping between localized states in disordered manner. (C) 2016 Elsevier Ltd. All rights reserved.