Tunable dielectric properties of niobium (Nb) doped CaCu3Ti4O12 nanocubes synthesized via facile molten salt route

Abstract

Doping induced tuning of dielectric constant of nanomaterials has huge technological importance, but its realization is limited by lack of synthetic protocols for uniform dielectric nanostructures, with controlled doping. Here, nanocubes of niobium doped calcium copper titanate (Nb-doped CCTO) is realized through molten salt route and the effect of Nb doping on tunability of dielectric behavior is reported. Particular focus is to minimize the significant dielectric loss which is practical concern of CCTO based giant dielectric materials. The structural and compositional properties of as synthesized powders and sintered pellets are analyzed by X-ray diffraction, field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. XRD analysis carried out on the samples confirmed single phase formation and indicated overall increase in lattice constant. The surface morphology of the molten salt derived product shows nanocubes with size in the range of 250–280 nm. Energy dispersive X-ray spectroscopy pattern confirmed the presence of Nb in doped samples. The dielectric response of sintered CaCu3Ti4−xNbxO12 samples studied by precision LCR meter suggest that although Nb substitution in CCTO reduces the dielectric constant but dielectric loss had lower values than those of undoped CCTO.