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Cr doped ZnO (x = 0-0.04) nanoceramics was successfully synthesized by high energy ball milling (HEBM) technique. The structural and electrical properties of the synthesized sample has been studied in detail. The doping of Cr into ZnO has... more
Cr doped ZnO (x = 0-0.04) nanoceramics was successfully synthesized by high energy ball milling (HEBM) technique. The structural and electrical properties of the synthesized sample has been studied in detail. The doping of Cr into ZnO has been verified by X-ray diffraction (XRD) and also from the variation in structural parameters. Rietveld refinement XRD pattern of calcined sample showed the hexagonal wurtzite structure and it did not induce impurity phases. From the XRD, it has been confirm that maximum result confirms that up to 4 atomic% of Cr can be doped into ZnO. The strain of the sample reduced with increase in particle size. After sintering, there is a growth of particle size of Cr doped ZnO sample. The impedance spectroscopy data shows a single semicircle in the high frequency region corresponding to the bulk properties of the nanoceramic sample. The decrease in real part of the impedance with temperature suggests the NTCR behavior of the sample in the temperature range of...
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Single phaseZn0.99Cu0.01O ceramic nanopowder was successfully synthesized by solid state reaction technique. X-ray diffraction studies of synthesized powder reveals single phase, hexagonal wurtzite structure and belongs to space group of... more
Single phaseZn0.99Cu0.01O ceramic nanopowder was successfully synthesized by solid state reaction technique. X-ray diffraction studies of synthesized powder reveals single phase, hexagonal wurtzite structure and belongs to space group of p63mc. No secondary peak in the XRD pattern shows the incorporation of Cu 2+ ion into the ZnO lattice rather than the interstitial one. Compare with pure ZnO(50nm),the average crystallite size of Zn0.99Cu0.01O (55nm) is higher. The substitution of Cu in ZnO results in contraction of the atoms. Electrical properties of the material has been studied by using Impedance Spectroscopy in the frequency range100Hz-1MHz and temperature range (300 0 c- 500 0 c) follow non-Debye relaxation process. The ac conductivity of Zn0.99Cu0.01O. lesser than ZnO which follow
In this work, high energy ball milling (HEBM) technique has been employed to successfully synthesize a series of Cu-doped ZnO nanoceramics (Zn 1-x Cu x O) with Cu concentration x = 0, 0.01, 0.02, 0.03 and 0.04. The synthesized nanoceramic... more
In this work, high energy ball milling (HEBM) technique has been employed to successfully synthesize a series of Cu-doped ZnO nanoceramics (Zn 1-x Cu x O) with Cu concentration x = 0, 0.01, 0.02, 0.03 and 0.04. The synthesized nanoceramic was analysed by XRD, FESEM, TEM, Uv-Vis-DRS. The structural, microstructural and optical properties of the synthesized sample with different duration of milling, doping concentration and temperature has been investigated. X-ray diffraction result indicates that the samples are wurtzite structure with single phase. A decrease in peak intensity was observed with increase in milling time. 10h milled Cu doped ZnO sample shows single phase. After calcination at 900 ºC in x = 0.04 few peaks related to CuO was observed indicating the solubility limit of Cu in ZnO is 3 atomic%. With increase in milling time crystallite decreases where as strain increases however after calcination crystallite increases where as strain decreases. After calcination peak inten...
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In the present work, Ni doped ZnO nanoparticles (Zn1−xNixO, x = 0,0.01) has been synthesized by High Energy Ball Milling technique. The synthesized nanoparticles have been characterized by XRD, UV-Vis spectroscopy and LCR meter. The XRD... more
In the present work, Ni doped ZnO nanoparticles (Zn1−xNixO, x = 0,0.01) has been synthesized by High Energy Ball Milling technique. The synthesized nanoparticles have been characterized by XRD, UV-Vis spectroscopy and LCR meter. The XRD studies revealed that the synthesized nanoparticles are single phase, hexagonal wurtize structure and belongs to a space group of P63 mc. There is shifting of most intense XRD peaks toward higher diffraction angle with Ni doping. The lattice parameter and average crystallite size decreases with Ni doping. Doping of Ni reduces the band gap of ZnO. This is attributed to the sp-d exchange interaction between the ZnO band electrons and localized d electrons of Ni2+ ions. The ac conductivity increases with increase in temperature and frequency, but the value decreases with Ni doping.
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Ca doped ZnO (Zn1−xCaxO, x = 0,0.01 and 0.02) ceramics were synthesized by simple solid state reaction route. Structural characterization was carried out by X-ray diffraction (XRD) technique. The modulus and ac conductivity of the... more
Ca doped ZnO (Zn1−xCaxO, x = 0,0.01 and 0.02) ceramics were synthesized by simple solid state reaction route. Structural characterization was carried out by X-ray diffraction (XRD) technique. The modulus and ac conductivity of the synthesized ceramics were analyzed by an impedance analyzer. The chemical composition of the synthesized ceramics was confirmed by EDX. The analysis of the XRD peaks revealed the hexagonal wurtzite structure, P63 mc space group for all compositions. The absence of extra peaks in the diffraction patterns indicate that the synthesized ceramics are in single phase. The crystallite size of ZnO decreases with Ca doping and also with increasing concentration of Ca. EDX analysis shows the presence of Ca in ZnO lattice. The frequency dependence imaginary part of modulus suggests the temperature dependent relaxation phenomena in the synthesized ceramics. The sign of long range to short range transition of charge carriers was observed in Ca doped ZnO ceramics. Incre...
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Cu doped ZnO nanoparticles abbreviated as Zn1−xCuxO (x = 0, 0.01 and 0.03) were synthesized by mechanical alloying. The change in structure, morphology, band gap and dielectric properties of the synthesized nanoparticles were investigated... more
Cu doped ZnO nanoparticles abbreviated as Zn1−xCuxO (x = 0, 0.01 and 0.03) were synthesized by mechanical alloying. The change in structure, morphology, band gap and dielectric properties of the synthesized nanoparticles were investigated by XRD, FE-SEM, FTIR, UV–Vis and impedance analyzer respectively. The incorporation of the dopant Cu into ZnO hexagonal wurtzite structure has been verified by X-ray diffraction (XRD) and the Cu doping on the structural bonding of ZnO has been verified by fourier transformation infrared spectra (FTIR).The XRD spectra shows that all the synthesized nanoparticles are single phase, hexagonal wurtzite structure and belong to the space group of P63mc.Crystallite size of Cu doped ZnO (15 nm) nanoparticles is smaller than pure ZnO (18 nm) and peak broadening exists in the system. FE-SEM analysis indicates that Cu doping affects the surface morphology of ZnO. The band gap (Eg) of ZnO decreases with Cu doping which can be attributed to sp-d exchange interaction between the ZnO band electrons and localized d electrons of Cu2+ ions. The dielectric constant of ZnO decreases with Cu doping.
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Single phase polycrystalline with = 0, 0.01 and 0.02 were synthesized by conventional solid state reaction method. The X-ray diffraction shows that the ceramic samples has hexagonal Wurtzite structure with a space group of p63mc and... more
Single phase polycrystalline with = 0, 0.01 and 0.02 were synthesized by conventional solid state reaction method. The X-ray diffraction shows that the ceramic samples has hexagonal Wurtzite structure with a space group of p63mc and average crystallite size in the range 52 - 88 nm. The dielectric and electrical properties were studied within the temperature range 30 °C to 500 °C under air atmosphere as function of frequency (10 kHz). The electrical properties of grain interior and grain boundary have been studied by using the impedance spectroscopy and follow the non-Debye relaxation process. It was observed that the AC conductivity of ceramic samples following the Universal power law within the frequency range 1kHz to 1 MHz. The activation energy of Pure is 0.29 eV was calculated by using the Arrhenius-relation with in temperature range 300 - 500 °C, which is increased to (0.40 eV ) when = 0.02 of at 10 kHz . The peaks attributed at 1415 cm-1 () and 1413 cm-1 () in FT-IR measuremen...