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Effect of calcination temperature on the structural, optical and magnetic properties of pure and Fe-doped ZnO nanoparticles

Singh R. P. P., Hudiara I. S., Rana S. B.

Materials Science Poland

2016

Vol. 34, No. 2

451--459

In the present study, pure ZnO and Fe-doped ZnO (Zn0.97Fe0.03O) nanoparticles were synthesized by simple coprecipitation method with zinc acetate, ferric nitrate and sodium hydroxide precursors. Pure ZnO and Fe-doped ZnO were further calcined at 450 ºC, 600 ºC and 750 ºC for 2 h. The structural, morphological and optical properties of the samples were characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and UV-Vis absorption spectroscopy. The X-ray diffraction studies revealed that the as-synthesized pure and doped ZnO nanoparticles have hexagonal wurtzite structure. The average crystallite size was calculated using Debye-Scherrer’s formula. The particle size was found to be in nano range and increased with an increase in calcination temperature. SEM micrographs confirmed the formation of spherical nanoparticles. Elemental compositions of various elements in pure and doped ZnO nanoparticles were determined by EDX spectroscopy. UV-Vis absorption spectra showed red shift (decrease in band gap) with increasing calcination temperature. Effect of calcination on the magnetic properties of Fe-doped ZnO sample was also studied using vibrating sample magnetometer (VSM). M-H curves at room temperature revealed that coercivity and remanent polarization increase with an increase in calcination temperature from 450 ºC to 750 ºC, whereas reverse effect was observed for magnetization saturation.

Physical properties of polyazomethine thin films doped with iodine

Hajduk B., Weszka J., Jarząbek B., Jurusik J., Domański M.

Journal of Achievements in Materials and Manufacturing Engineering

2007

Vol. 24, nr 2

67-70

Purpose: The aim of this paper is to show influence of doping 1,4-phenylene-methylenenitrilo-1,4- phenylenenitrilomethylene (PPI) with iodine and to propose doping mechanism and its impact on electronic structure of doped PPI thin films. Design/methodology/approach: Influence of iodine doping on electronic structure of polyazomethine thin films was investigated. Optical absorption spectra, XRD spectra and AFM images of doped PPI thin films were recorded. Findings: Doping mechanism relys on removing one electron from PPI pi-system by 12 molecules and forming counterions 13-. Formation of positive polaron means that doping of polyazomethine PPI is p - type. Research limitations/implications: Influence of iodine doping on electrical properties (with increasing of temperature) of PPI thin layers will be checking with Kethley appliance. We plan these measurements to be done in the foreseeable future. Practical implications: Iodine doping of thin PPI films process could results in better electrical conductivity of PPI, so doped polyazomethine films could find some applications for photonic and optoelectronic devices. Originality/value: Conjugated PPI is rarely enough reported but it is very interesting material as it has nitrogen atom in the backbone and it is isoelectronic counterpart of polyparaphenylenevinylene (PPV). This paper show that doping influences on surface morphology, cristallinity and optical properties of polymer. Furthermore, doping mechanism and changes of polymer electronic structure have been proposed in this paper.