Abstract
SEM image for 10 wt% Er@NiO, energy gap and dielectric constant variation with Er doping contnt in NiO.
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•First time Er@NiO NPs synthesis was done facilely by flash combustion process.•Monophasic cubic structure was confirmed from XRD and Rietveld refinement process.•Crystallite size reduced from 27 to 8 nm and also the grain size with Er doping in NiO.•Reduction in energy gap from 3.50 to 3.17 eV was noticed by Er doping in NiO.•High dielectric constant was noticed i.e. in range of 65–115 at 3 kHz and 18–36 at 3 MHz.
A facile synthesis of erbium doped nickel oxide (Er@NiO) was accomplished via combustion route at 550 °C within 2 h. Cubic phase of all Er@NiO samples was confirmed by X-ray diffraction (XRD) and Rietveld refinement methods. All XRD profiles were fitted well by Rietveld. XRD data was used to determine the values of size, dislocations, strain and the size was reduced from 26 to 8 nm on rising the Er content in NiO. Vibrational spectroscopy also approved the synthesis of NiO without any impurity content at all Er concentrations. The composition of Ni, O and Er was evaluated by EDX and their uniform dispersal in final product was confirmed by SEM e-mapping. Further, SEM study confirms very compact nanostructure of final products and the size reduction was observed by Er content. Kubelka-Munk methodology was employed to attain the bandgap of all Er@NiO NPs and lies between 3.17 and 3.50 eV. The ε' values are lies between 65–115 at 3 kHz and 18–36 at 3 MHz, however, it was higher for 5 wt% Er@NiO NPs compare to other at 3 kHz and lower after 7 kHz. The ac conductivity and conduction behaviour were also inveterate and conferred.