Synthesis and characterization of Cu-doped ZnCdO nanomaterials with improved dielectric and impedance properties for potential applications (original) (raw)
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INVESTIGATIONS ON STRUCTURAL, DIELECTRIC AND OPTICAL PROPERTIES OF Cu-DOPED ZnO NANOPARTICLES
The structural, morphological, optical and electrical studies of Cu doped Zinc Oxide (ZnO) nanoparticles which were synthesized by hydrothermal method. The PXRD results confirmed that the synthesized material is polycrystalline ZnO and the average crystallite size of the Cu doped ZnO were determined by using the Scherrer's formula. Various functional groups were analyzed by using the FTIR analysis. Surface morphological and chemical compositions were analyzed using SEM and EDX. The optical properties were carried out using transmission and Photoluminescence spectrum. The dielectric properties of the Cu doped ZnO nanoparticles dielectric constant, dielectric loss, AC conductivity were analyzed in various frequencies and temperatures at specific conditions.
Journal of Materials Science & Technology, 2014
Here, undoped and Cu doped ZnO nanoparticles (NPs) have been prepared by chemical co-precipitation technique. X-ray diffraction (XRD) results reveal that Cu ions are successfully doped into ZnO matrix without altering its wurtzite phase. The single wurtzite phase of ZnO is retained even for 10 wt% Cu doped ZnO sample. It is observed from the electron microscopy results that higher level of Cu doping varies the morphology of ZnO NPs from spherical to flat NPs. Moreover, the particle size is found to increase with the increase in Cu doping level. Raman spectroscopy results further confirm that Cu dopant has not altered the wurtzite structure of ZnO. Impedance spectroscopy results reveal that the dielectric constant and dielectric loss have increasing trend with Cu doping. Cu doping has been found to slightly decrease the bactericidal potency of ZnO nanoparticles.
Structural investigations on Cu 2+ ions doped ZnCdO nanopowder
This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright " Cu 2+ ion doped ZnCdO nanopowder is prepared by simple solution method. " Powder XRD pattern conforms the prepared powder is in the nanoscale. " Site symmetry for copper ion is tetragonal distorted octahedral site symmetry. a b s t r a c t Cu 2+ ion doped ZnCdO composite powder is synthesized at room temperature by using mild and simple solution method and it is characterized by Powder X-ray diffraction, SEM, EDX and several spectroscopic techniques. Powder XRD pattern of the prepared powder confirms the crystallite size is in nanoscale. PL spectrum exhibited the bands in the UV and blue region and FT-IR spectrum clearly evidences the characteristic absorption bands related to the metal oxides and as well as some other organic molecules. Optical absorption and EPR studies suggested that Cu 2+ ion enters into the lattice as tetragonally elongated octahedral symmetry, for which crystal field, Spin-Hamiltonian, hyperfine splitting and bonding parameters are evaluated.
International Journal of Nano and Biomaterials, 2017
Cu doped ZnO nanoparticles abbreviated as Zn 1-x Cu x O (x = 0, 0.01 and 0.03) were synthesised by high energy ball milling (HEBM) technique. The structural, morphological, optical and dielectric properties of the synthesised nanoparticles were carried out by XRD, FTIR, UV-Vis and impedance analyser, respectively. The incorporation of the dopant Cu into ZnO hexagonal wurtzite structure has been verified by X-ray diffraction (XRD). The effect of Cu doping on the structural bonding of ZnO has been verified by Fourier transformation infrared (FTIR) spectra. The XRD spectra shows that all the synthesised nanoparticles are single phase, hexagonal wurtzite structure and belong to the space group of p6 3 mc. Compared to pure ZnO (18 nm), the crystallite size of Cu doped ZnO (15 nm) is smaller and peak broadening exists in the system. A similar feature of FTIR spectra has been observed for all samples, which supports the hexagonal wurtzite structure of ZnO even after Cu doping. The band gap (E g) of ZnO decreases with Cu doping which can be attributed to sp-d exchange interaction between the ZnO band electrons and localised d electrons of Cu 2+ ions. The dielectric constant of ZnO decreases with Cu doping.
Structural, Optical and Dielectric Properties of Fe Doped CuO Nanoparticles
Undoped and Fe doped CuO nanoparticles were prepared by sol-gel method with different concentration (x=0, 0.1, 0.3%) at 300˚C. The obtained nanoparticles were characterised by XRD, SEM with EDAX spectra, UV-Visible, FL and Dielectric properties. XRD pattern exhibit the presence of cupric oxide (CuO) with monoclinic phase. The observed shift in the absorption edge from 204 to 557 nm with (pure CuO) to 1.0eV (CuO: Fe 1%) and 0.9eV (CuO: Fe 3%). From the FL spectra the peak absorbed at 823nm, the band gap is 1.5eV. The dielectric constant and loss decreases with an increasing frequency at room temperature for pure CuO.
Studies of electrical properties of Cu doped ZnS nanoparticles synthesised by Solvothermal route
Nanoparticles of ZnS and ZnS doped with 4 mol% Cu was synthesized by solvothermal method. The X-ray diffraction pattern showed the typical interplanar spacings corresponding to the cubic phase of ZnS. The transmission electron microscopy image revealed the particle size of the order of 5 nm. The AC conductivity of the ZnS nanocrystals was measured at different constant temperatures for the frequency range in between 100 Hz and 1 MHz. The AC conductivity of the materials showed an exponential increase with frequency of the applied field similar to that of semiconducting materials.
Synthesis of zinc-doped copper oxide nanoparticles: Structural and morphological characterizations
Reported here is the various levels of Zn incorporated CuO nanocrystals derived from a simple chemical precipitation method. The prepared nanocrystals were studied for structural, functional and morphological analysis. The X-ray Diffraction (XRD) analysis of the prepared nanocrystals revealed the monoclinic crystal structure with the sizes in the range between 18 and 25 nm. The Fourier Transform Infrared Spectroscopy (FT-IR) of the prepared nanocrystals was recorded in the range of 4000-400 cm-1 and its further supporting the formation of CuO nanocrystals. The morphology of the prepared products analyzed with Field Emission-Scanning Electron Microscopy (FE-SEM) and the results revealed the synthesized nanocrystals are well distributed and flaky nature in morphology.
Synthesis And Dielectric Properties Of Nanocrystalline Cd doped CuFe2O4
ABSTRACT:- The enhanced dielectric properties of nanocrystalline materials exhibiting unusual properties play a vital role in the development of new materials. The electrical properties of nanostructured materials are many times superior to their bulk form and depend strongly on size, shape, composition and preparation conditions. Nanosized Cd doped CuFe2O4 in different grain sizes were prepared for the present study. The crystal structure and particle size were determined using X-ray diffraction technique .. The dielectric properties of the samples were systematically analyzed using a HIOKI 3532-50 LCR HiTESTER over the frequency range from 100 Hz to 1MHz and over the temperature from 100 °C to 700° C. The variation of dielectric constant, dielectric loss and ac electrical conductivity for all the samples were studied. The dielectric constants of all the samples are high at low frequencies that decrease rapidly when the frequency is increased.
Cu-ZnO Nanostructures Synthesis and Characterization
Iraqi journal of science, 2021
5wt% copper doped zinc oxide (Cu-ZnO) nanostructures were prepared via the hydrothermal technique at different temperatures of 70, 100, 130, 160 and 190oC. UV spectroscopy, FE-SEM microscopy, XRD crystallography, and EDS measurements were used for nanostructure characterization. UV spectroscopy indicated a red shift for the absorption peaks, and hence a blue shift for the energy gap values, as temperature increased from 70 to 190oC. FE-SEM microscopy showed an increase in the average lengths and diameters of the nanostructures following a similar increase in temperature. XRD crystallography indicated decent structural patterns for Cu-ZnO nanostructures with an increase in crystallite size upon temperature increase. Interestingly, three unprecedented extra indices appeared in the structural pattern at 190oC, which might indicate a configuration of hexagonal crystallite with three extra planes. EDS measurements indicated the sole presence of Cu, Zn and O.