Doped ZnO Nanowires Obtained by Thermal Annealing

2007 ◽  
Vol 7 (2) ◽  
pp. 700-703
Author(s):  
C. X. Shan ◽  
Z. Liu ◽  
C. C. Wong ◽  
S. K. Hark

Doped ZnO nanowires were prepared in a very simple and inexpensive thermal annealing method using ZnSe nanowires as a precursor. As doped, P doped, and As/P codoped ZnO nanowires were obtained in this method. X-ray diffraction shows that the zincblende ZnSe nanowires were converted to doped wurtzite ZnO nanowires. The incorporation of the dopants was confirmed by energy dispersive X-ray spectroscopy. The doping concentration could be adjusted by changing the annealing temperature and duration. Scanning electron microscopy indicated that the morphology of the ZnSe nanowires was essentially retained after the annealing and doping process. Photoluminescence spectroscopy also verified the incorporation of the dopants into the nanowires.

2007 ◽  
Vol 7 (2) ◽  
pp. 700-703 ◽  
Author(s):  
C. X. Shan ◽  
Z. Liu ◽  
C. C. Wong ◽  
S. K. Hark

Doped ZnO nanowires were prepared in a very simple and inexpensive thermal annealing method using ZnSe nanowires as a precursor. As doped, P doped, and As/P codoped ZnO nanowires were obtained in this method. X-ray diffraction shows that the zincblende ZnSe nanowires were converted to doped wurtzite ZnO nanowires. The incorporation of the dopants was confirmed by energy dispersive X-ray spectroscopy. The doping concentration could be adjusted by changing the annealing temperature and duration. Scanning electron microscopy indicated that the morphology of the ZnSe nanowires was essentially retained after the annealing and doping process. Photoluminescence spectroscopy also verified the incorporation of the dopants into the nanowires.


Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 118 ◽  
Author(s):  
Ho-Yun Lee ◽  
Chi-Wei He ◽  
Ying-Chieh Lee ◽  
Da-Chuan Wu

Cu–Mn–Dy resistive thin films were prepared on glass and Al2O3 substrates, which wasachieved by co-sputtering the Cu–Mn alloy and dysprosium targets. The effects of the addition ofdysprosium on the electrical properties and microstructures of annealed Cu–Mn alloy films wereinvestigated. The composition, microstructural and phase evolution of Cu–Mn–Dy films werecharacterized using field emission scanning electron microscopy, transmission electronmicroscopy and X-ray diffraction. All Cu–Mn–Dy films showed an amorphous structure when theannealing temperature was set at 300 °C. After the annealing temperature was increased to 350 °C,the MnO and Cu phases had a significant presence in the Cu–Mn films. However, no MnO phaseswere observed in Cu–Mn–Dy films at 350 °C. Even Cu–Mn–Dy films annealed at 450 °C showedno MnO phases. This is because Dy addition can suppress MnO formation. Cu–Mn alloy filmswith 40% dysprosium addition that were annealed at 300 °C exhibited a higher resistivity of ∼2100 μΩ·cm with a temperature coefficient of resistance of –85 ppm/°C.


2010 ◽  
Vol 663-665 ◽  
pp. 542-545 ◽  
Author(s):  
Bing Jie Zhu ◽  
Xin Wei Wang ◽  
Mei Fang Zhu ◽  
Qing Hong Zhang ◽  
Yao Gang Li ◽  
...  

The PANI/ITO conducting nanocomposites have been synthesized by in-situ polymerization. The obtained nanocomposites were characterized by X-ray diffraction pattern, scanning electron microscopy and Fourier transform infrared. Electrical conductivity measurements on the samples pressed into pellets showed that the maximum conductivity attained 2.0 ± 0.05 S/cm for PANI/ITO nanocomposites, at ITO doping concentration of 10 wt%. The results of the present work may provide a simple, rapid and efficient approach for preparing PANI/ITO nanocomposites.


2010 ◽  
Vol 24 (30) ◽  
pp. 5973-5985
Author(s):  
M. GUNES ◽  
H. GENCER ◽  
T. IZGI ◽  
V. S. KOLAT ◽  
S. ATALAY

NiFe 2 O 4 nanoparticles were successfully prepared by a hydrothermal process, and the effect of temperature on them was studied. The particles were annealed at various temperatures ranging from 413 to 1473 K. Studies were carried out using powder X-ray diffraction, scanning electron microscopy, infrared spectroscopy, differential thermal analysis, thermogravimetric analysis and a vibrating sample magnetometer. The annealing temperature had a significant effect on the magnetic and structural parameters, such as the crystallite size, lattice parameter, magnetization and coercivity.


2013 ◽  
Vol 543 ◽  
pp. 63-67
Author(s):  
Jayabharathi Jayaraman ◽  
Jayamoorthy Karunamoorthy

A sensitive benzimidazole derivative fluorescent sensor for nanoparticulate ZnO has been designed and synthesized. The nanocrystalline ZnO, Ag doped ZnO and Cu doped ZnO have been synthesised by sol-gel method and characterized by powder X-ray diffraction, scanning electron microscopy (SEM) and UV-visible diffuse reflectance, photoluminescence and electrochemical impedance spectroscopies. The synthesized sensor emits fluorescence at 360 nm and this fluorescence is selectively enhanced by nanocrystalline ZnO. This technique is sensitive to detect and estimate ZnO at micro molar level. Impurities such as Ag and Cu do not hamper the sensitivity of this technique significantly. Keywords: Sensor, SEM, EDX, Impedance, Fluorescence


2015 ◽  
Vol 1088 ◽  
pp. 81-85 ◽  
Author(s):  
T.N. Myasoedova ◽  
Victor V. Petrov ◽  
Nina K. Plugotarenko ◽  
Dmitriy V. Sergeenko ◽  
Galina Yalovega ◽  
...  

Thin SiO2ZrO2films were prepared, up to 0.2 μm thick, by means of the sol–gel technology and characterized by a Scanning electron microscopy and X-ray diffraction. It is shown the presence of monoclinic, cubic and tetragonal phases of ZrO2in the SiO2matrix. The crystallites sizes depend on the annealing temperature of the film and amount to 35 and 56 nm for the films annealed at 773 and 973 K, respectively. The films resistance is rather sensitive to the presence of NO2and O3impurity in air at lower operating temperatures in the range of 30-60°C.


2010 ◽  
Vol 644 ◽  
pp. 113-116
Author(s):  
L.A. García-Cerda ◽  
Bertha A. Puente Urbina ◽  
M.A. Quevedo-López ◽  
B.E. Gnade ◽  
Leo A. Baldenegro-Perez ◽  
...  

In this study, HfxZr1-xO2 (0 < x < 1) thin films were deposited on silicon wafers using a dip-coating technique and by using a precursor solution prepared by the Pechini route. The effects of annealing temperature on the structure and morphological properties of the proposed films were investigated. HfxZr1-xO2 thin films with 1, 3 and 5 layers were annealed in air for 2 h at 600 and 800 °C and the structural and morphological properties studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD results show that the films have monoclinic and tetragonal structure depending of the Hf and Zr concentration. SEM photographs show that all films consist of nanocrystalline grains with sizes in the range of 6 - 13 nm. The total film thickness is about 90 nm.


2019 ◽  
Vol 27 (2) ◽  
pp. 228-237 ◽  
Author(s):  
Rashed T. Rasheed ◽  
Sariya D. Al-Algawi ◽  
Rosul M. N.

Manganese dioxide (MnO2) nanopowder has been synthesized by hydrothermal method. MnO2 was annealed at different temperatures (250, 400, 550, 700˚C). The crystal structure and surface morphology of these nanostructures were characterized by X-ray diffraction (XRD), Atomic Force Microscope (AFM) and Scanning Electron Microscopy (SEM). The catalase mimic activity (catalytic activity) of MnO2 against hydrogen peroxide (H2O2) was studied by using the new method and found that 400˚C is the best annealing temperature.


2017 ◽  
Vol 11 (2) ◽  
pp. 100-105 ◽  
Author(s):  
Song Wang ◽  
Yaping Wang ◽  
Kangning Sun ◽  
Xiaoning Sun

In this work, ?-tricalcium phosphate (?-TCP) was successfully prepared by the thermal transformation of amorphous calcium phosphate (ACP) precursor. ?-cyclodextrin (?-CD) was used for preparation of ACP precursor and played an important role in designing its special structure. The phase composition and microstructures of the obtained ?-TCP at different annealing temperature were analysed by X-ray diffraction and scanning electron microscope, and confirmed that ?-TCP can be prepared at 650?C for 3 h using ACP as precursor, which is much lower than the phase transition temperature of ?-TCP. Mechanical properties were tested 24 h after mixing the obtained ?-TCP with 30 wt.% of deionised water. The compressive strength and the flexural strength were 26.4MPa and 12.0MPa, respectively. The flexural strength was higher than that of ?-TCP prepared by other methods.


2012 ◽  
Vol 485 ◽  
pp. 144-148
Author(s):  
Jian Lin Chen ◽  
Yan Jie Ren ◽  
Jian Chen ◽  
Jian Jun He ◽  
Ding Chen

Preferentially oriented Al-doped ZnO thin films with doping concentration of 1, 2, 3, 5 and 10 mol% respectively were prepared on glass substrates via sol-gel route. The crystallinity of films was characterized by X-ray diffraction and the surface morphologies were observed by scanning electron microscopy. The results show that ZnO:Al films at low doping concentration (1, 2 mol%) grow into dense homogenous microstructure. However, as for high doping concentration (3, 5, 10 mol%), Al3+ precipitate in the form of amorphous Al2O3 and ZnO:Al films exhibit heterogeneous nucleation and exceptional growth of the big plate-like crystals at the interface of the amorphous Al2O3 and ZnO:Al matrix.


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