scholarly journals A Study of Microstructural Models of Li-doped ZnO Ceramic for Piezoelectric Application

2021 ◽  
pp. 21-38
Author(s):  
Sunday Ogochukwu Ali ◽  
Umaru Ahmadu ◽  
Moses Aderemi Olutoye ◽  
Oyeleke Olarinoye
Keyword(s):  
Grain Size ◽  
Crystallite Size ◽  
Hexagonal Wurtzite Structure ◽  
Hexagonal Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lithium Doping ◽  
A Value ◽  
Subsequent Decrease ◽  
Doped Zno

Structural and microstructural properties of Zn1-xLixO (0.00 ≤x≤ 0.50) ceramics were carried out using X-ray Diffraction (XRD) showed that the samples were polycrystalline with hexagonal wurtzite structure. The average crystallite size was estimated using three models, all of which showed decrement with increased lithium-doping. The crystallite size increased systematically, with the largest value being 200 nm in the Li-doped ZnO in x=0.3. However, microstrain was fairly constant for all doped samples with a value of ~0.006, the value for the pristine being 0.001. Of the three models, the comparison showed that the Scherer model had the smallest crystallite size due to the neglect of strain, whereas the W-H model had the largest in the doped samples, with crystallite size ~200 nm, but with subsequent decrease observed which is attributed to the assumption of isotropy in the model. The c/a ratio indicated a consistent hexagonal structure despite lithium-doping. Energy Dispersive Spectroscopy (EDS) showed that all the nominal elements compositions were present. A decrease in grain size with the increase in lithium-doping was observed with the lowest grain size (0.2 μm) observed in x=0.5, thus making it the specimen with the highest potential for piezoelectric application.

Dislocations, crystallite size, and planar faults in nanocrystalline ceria

2009 ◽  
Vol 24 (3) ◽  
pp. 228-233 ◽  
Author(s):  
S. R. Aghdaee ◽  
V. Soleimanian
Keyword(s):  
Grain Size ◽  
Dislocation Density ◽  
Crystallite Size ◽  
Cerium Oxide ◽  
Diffraction Line ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nanocrystalline Ceria ◽  
Hall Plot

The modified Williamson–Hall and Warren–Averbach methods were used successfully for analyzing experimentally observed anisotropic X-ray diffraction line broadening and for determining reliable values of crystallite size and dislocation density in cerium oxide. The modified Williamson–Hall plot gives 22.3(2) nm for volume-weighted crystallite size, while the modified Warren–Averbach produces 18.0(2) nm for area-weighted grain size. The dislocation density and effective outer cut-off radius of dislocations obtained from the modified Warren–Averbach method are 1.8(3)×1015 m−2 and 15.5(1) nm, respectively.

Optical Properties of Cu-Doped ZnO Films Prepared by Cu Solution Coating

2015 ◽  
Vol 15 (10) ◽  
pp. 7664-7670 ◽  
Author(s):  
Bunyod Allabergenov ◽  
Seok-Hwan Chung ◽  
Sungjin Kim ◽  
Byeongdae Choi
Keyword(s):  
Grain Size ◽  
Optical Properties ◽  
Hexagonal Wurtzite Structure ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Coating Method ◽  
Higher Temperature ◽  
Doped Zno ◽  
Process Energy ◽  
Beam Deposition

This work demonstrates the fabrication of Cu-doped ZnO films by Cu solution coating method. Cu ink was spin coated on ZnO thin films prepared by e-beam deposition. After curing and annealing at high temperatures, structural, morphological and optical properties of the films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and spectrofluorometer, respectively. The XRD results showed that ZnO films formed polycrystalline with a hexagonal wurtzite structure, and the grain size increased with increasing the annealing temperature from 500 to 850 °C. The changes in lattice parameters were caused by grain size, strain, and residual stress. Morphological analysis have revealed that the Cu-doped ZnO film after annealing at 500 °C has flat surface with uniformly distributed grain size, which became porous after higher temperature annealing process. Energy dispersive spectroscopy (EDS) and photoluminescence spectras have shown the presence of Zn, Cu, and O elements, and combined violet, blue, green and weak red emissions between 350 and 650 nm in the ZnO films, respectively.

Mechanical Alloying of Fe30Cu70

2007 ◽  
Vol 23 ◽  
pp. 63-66
Author(s):  
Virgiliu Călin Prică ◽  
George Arghir
Keyword(s):  
Grain Size ◽  
Milling Time ◽  
Mixing Enthalpy ◽  
X Ray Diffraction ◽  
Powder Morphology ◽  
X Ray ◽  
A Value ◽  
Average Grain Size ◽  
Milling Duration ◽  
Time Changes

Fe-Cu system is a binary alloys system, nevertheless very difficult. This paper presented the milling duration influence on ball-milled Fe30Cu70 alloys. After 16 hour of milling it has been concluded that true alloying at atomic level occurs during milling. The average grain size depends by milling time. Varying the milling time changes the powder morphology, their size and structure. We found that the complete fcc Fe –Cu solid solution is formed when the grain size of Fe-bcc reach a value about 10 nm, because at this value of crystallite the free energy for interface become less than interfaces energy. The milling duration have a strongly influence on solid solubility and phases form in Fe-Cu system. The phase formation for Fe30Cu70 (mass %) has been investigated by X-ray diffraction (XRD). The mixing enthalpy (positive in this system) also depends on alloy composition.

Rietveld refinement of transition metal doped ZnO

2008 ◽  
Vol 23 (S1) ◽  
pp. S36-S41 ◽  
Author(s):  
D. A. A. Santos ◽  
A. D. P. Rocha ◽  
M. A. Macêdo
Keyword(s):  
Transition Metal ◽  
Rietveld Refinement ◽  
Sol Gel ◽  
Hexagonal Wurtzite Structure ◽  
X Ray Diffraction ◽  
Ionic Radii ◽  
X Ray ◽  
Sol Gel Process ◽  
Doped Zno ◽  
Metal Doped

Nanocrystals of Zn1−xMxO (M=Mn, Co, or Ni) were grown using proteic sol-gel process, and the crystalline phases were identified by X-ray diffraction and Rietveld refinement. The nanocrystals have hexagonal wurtzite structure, with space group P63mc. The insertion of Mn2+ in the place of Zn2+ provoked an increase in the size of the nanocrystals, and the insertion of Co2+ or Ni2+ caused a reduction in the sizes of the nanocrystals, as compared to pure ZnO. This occurred because these three transition metals have very different ionic radii (Co2+=0.58 A˚, Mn2+=0.66 A˚, Ni2+=0.55 A˚, and Zn2+=0.60 A˚).

X-ray diffraction analyses of 3D MgO-based replicas of diatom microshells synthesized by a low-temperature gas/solid displacement reaction

2005 ◽  
Vol 20 (4) ◽  
pp. 306-310 ◽  
Author(s):  
M. S. Haluska ◽  
I. C. Dragomir ◽  
K. H. Sandhage ◽  
R. L. Snyder
Keyword(s):  
Grain Size ◽  
Low Temperature ◽  
Crystallite Size ◽  
Gas Phase ◽  
Grain Growth ◽  
Annealing Time ◽  
Displacement Reaction ◽  
X Ray Diffraction ◽  
Fourier Methods ◽  
X Ray

The nanostructural features of the gas-phase displacement reaction 2Mg(g)+SiO2→2MgO(s)+{Si}, where SiO2 is in the form of diatom shells were studied via X-ray diffraction and Fourier methods. Diatomaceous powder heated to 700 °C in a sealed graphite cell in the presence of Mg vapor formed MgO via a displacement reaction. Warren-Averbach analysis performed on samples reacted for different times showed an initial sharp MgO grain size distribution which broadened with time. New MgO crystallization was shown to occur until about 60 min, whereafter only MgO grain growth occurred. Median MgO crystallite size increased from 7.5 to 24.9 nm during this period, whereas microstrain decreased dramatically past 60 min annealing time.

Preparation and Characterization of Ag and Co Doped ZnO Nano Particles

2012 ◽  
Vol 584 ◽  
pp. 248-252
Author(s):  
B. Sankara Reddy ◽  
S. Venkatramana Reddy ◽  
R.P. Vijaya Lakshmi ◽  
N. Koteeswara Reddy
Keyword(s):  
Blue Emission ◽  
Photo Luminescence ◽  
Hexagonal Structure ◽  
Nano Particles ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Doped Zno ◽  
Co Precipitation ◽  
Co Doped

Pure ZnO and Ag, Co doped ZnO nano particles [Zn1-xAgxCoyO, where x = 0.00 and 0.05, y = 0.05] were synthesized by chemical co precipitation method without use of surfactant. All the prepared samples calcinated in 1 hour at 500oC, after that the morphology of the samples were evaluated by Scanning Electron Microscope (SEM). The X- ray diffraction (XRD) results indicated that the synthesized co-doped ZnO nano crystals had the pure hexagonal structure without any significant change in the structure affected by Ag and Co substitution. Dopant elements Ag and Co are present in the ZnO host material and conformed by Energy Dispersive Analysis of X-ray Spectra (EDAX). The incorporation of Ag+ in the place of Zn2+ has made a considerable decrease in the size of nano crystals as compared to pure ZnO nano particles (It is to be noted that Co should be kept constant at 5 mol %). Blue emission was observed by Photo Luminescence (PL) Spectra.

scholarly journals Performance Improvement of UV Photodetectors using Cd-doped ZnO Nanostructures

2021 ◽  
Author(s):  
Fatemeh Abbasi ◽  
Fahimeh Zahedi ◽  
Mohammad hasan Yousefi
Keyword(s):  
Morphological Characteristics ◽  
Hexagonal Wurtzite Structure ◽  
X Ray Diffraction ◽  
Uv Photodetector ◽  
Pure Zinc ◽  
Current Time ◽  
X Ray ◽  
Metal Semiconductor Metal ◽  
Current Voltage ◽  
Doped Zno

Abstract The present research performed thermal decomposition to synthesize pure zinc oxide (ZnO) and cadmium-doped ZnO (ZnO:Cd) nanorods with ZnO to Cd weight ratios of 93:7, 95:5 and 97:3. Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and photoluminescence (PL) spectroscopy were performed and current/voltage and current/time measured to determine the optical, structural and morphological characteristics of ZnO and ZnO:Cd. The XRD results suggested the hexagonal wurtzite structure of all the samples and the successful incorporation of Cd into the ZnO structures. This incorporation caused a spherical to rod-like change in the shape of the nanostructures. An intense and sharp peak was observed at 380 nm (3.26 eV) in the UV region of the PL spectra of all the samples. A UV photodetector fabricated on the basis of ZnO and ZnO:Cd nanorods with a metal-semiconductor-metal configuration showed the significant photocurrent and photosensitivity of the ZnO:Cd samples in the UV photodetection application. The sensitivity of the fabricated ZnO photodetectors with Cd percentages of 0, 3, 5 and 7% was respectively obtained as 110.62, 463.28, 762.40 and 920.30. The fastest photoresponse, with a rise and decay time of 2.5 and 4 s, respectively, was associated with the sample doped with 5% Cd.

Synthesis of Al-Doped ZnO Nanoparticles and its Electromagnetic Performance

2010 ◽  
Vol 143-144 ◽  
pp. 271-276
Author(s):  
Yan Qiang Jia ◽  
Dong Mei Shi ◽  
Jun Yan
Keyword(s):  
Doping Concentration ◽  
Hexagonal Wurtzite Structure ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Al Content ◽  
Homogeneous Precipitation Method ◽  
Doped Zno ◽  
Zno Crystal ◽  
Electromagnetic Performance

Al-doped ZnO (AZO) nanoparticles were synthesized by using homogeneous precipitation method from Zn(AC)2•2H2O and Al(NO3)3•9H2O. X-ray diffraction (XRD) showed that the AZO nanoparticles were well assigned to hexagonal wurtzite structure, and that the Al3+ did enter the ZnO crystal lattice to substitute the position of Zn2+. Results from scanning electron microscope (SEM) showed that with increasing Al content, the the size of ZAO particles decreased. When Al content was 5 mol%, gives a more homogeneous and finer microstructure. At last, study the electromagnetic performance of AZO particles with different doping concentration of Al3+.

scholarly journals Structural and optical characteristic of 1-(4-Methylsulfonyl Phenyl)-3-(4-n, n Dimethyl (amino Phenyl)-2-Propen- 1-One (MSPPP) Chalcone doped ZnO nanoparticles

NanoNEXT ◽  
2021 ◽  
pp. 28-34
Author(s):  
Mohana F. Attia ◽  
Abdelrahman A. Elbadawi
Keyword(s):  
Zno Nanoparticles ◽  
Diffuse Reflection ◽  
Energy Gap ◽  
Hexagonal Wurtzite Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystallite Sizes ◽  
Order Of Magnitude ◽  
Doped Zno

The purpose of this paper is to investigate the structural and optical characteristics of 1-(4-Methylsulfonyl Phenyl)-3-(4-n, n Dimethyl (amino Phenyl)-2-Propen- 1-One (MSPPP) Chalcone doped in ZnO nanoparticles. Part of the aim is to study the characterization of chalcone doped ZnO nanoparticles by several techniques such as X-ray diffraction, Scanning electron microscope, FTIR spectroscopy, and diffuse reflection spectra.  All doped samples showed a hexagonal wurtzite structure. This study has shown that the crystallite size of pure ZnO varied from 23.50 to 27.45 nm and when increasing the chalcone percentage by 0.5 and 1.5%, has increased the crystallite sizes in the range of 33.40–33.80 nm and 33.80–36.20 nm, respectively. The value of the energy gap (Eg) for ZnO nanoparticles was 3.14 eV. For 0.5 and 1.5% chalcone doped ZnO, the energy gap decreased by an order of magnitude 0.16 eV.

scholarly journals CVD PREPARED Mn-DOPED ZnO NANOWIRES

2017 ◽  
Vol 24 (1&2) ◽  
pp. 125-130
Author(s):  
T.L. Phan ◽  
R. Vincent ◽  
D. Cherns ◽  
N.X. Nghia
Keyword(s):  
Magnetic Measurements ◽  
Chemical Vapor ◽  
Hexagonal Structure ◽  
Zno Nanowires ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wavenumber Range ◽  
Doped Zno ◽  
Diffraction Patterns ◽  
Mn Doped

Mn-doped ZnO nanowires prepared by chemical vapor deposition (CVD) were obtained in the temperature range of 450–500°C. X-ray diffraction patterns, SEM and TEM images indicate that crystals with a hexagonal structure grow along the c axis. At low Mn-doped concentrations, photoluminescence (PL) and Raman scattering (RS) spectra are almost independent of the Mn doping. However, the increase in concentration of Mn above 1.6 at% weakens significantly the PL signal and the RS-lines intensity in the low wavenumber range of 300–480 cm-1, and concurrently increases the RS-lines intensity in the higher wavenumber range of 480-700 cm-1.. Magnetic measurements determined the Curie temperature of Mn-doped ZnO nanowire to be about 37 K.

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