scholarly journals Synthesis and Characterization of ZnTe Hierarchical Nanostructures

2012 ◽  
Vol 2012 ◽  
pp. 1-5
Author(s):  
Baohua Zhang ◽  
Fuqiang Guo ◽  
Wei Wang

Single-crystalline ZnTe hierarchical nanostructures have been successfully synthesized by a simple thermal evaporation technology. The as-prepared products were characterized with X-ray diffraction (XRD), scanning electron microcopy (SEM), transmission electron microscope (TEM), and photoluminescence spectrum (PL). These results showed that the ZnTe hierarchical nanostructures consisted of nanowires and nanolumps. The room temperature PL spectrum exhibited a pure green luminescence centered at 545nm. The growth mechanism of hierarchical nanostructure was also discussed.

2011 ◽  
Vol 10 (01n02) ◽  
pp. 237-240 ◽  
Author(s):  
J. P. BORAH ◽  
C. BORGOHAIN ◽  
K. C. SARMA ◽  
K. K. SENAPATI ◽  
P. PHUKAN

The synthesis of composite magnetic nanomaterials has received increasing attention due to their electronic, magnetic, catalytic, and chemical or biological sensing properties. We have prepared cobalt ferrite–zinc sulfide nanocomposites by a chemical route. The synthesized nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and photoluminescence spectrometer (PL). The fluorescent magnetic nanoparticles (FMNPs) had a typical diameter of 30±5 nm and saturation magnetization of 5.8 emu g-1 at room temperature. So, these FMNPs may be potentially applied in different fields such as optoelectronic devices, biolabeling, imaging, drug targeting, bioseparation, magnetic fluid hyperthermia, etc.


2014 ◽  
Vol 602-603 ◽  
pp. 19-22 ◽  
Author(s):  
Lin Qiang Gao ◽  
Hai Yan Chen ◽  
Zhen Wang ◽  
Xin Zou

Nanoscale LiTaO3 powders with perovskite structure were synthesized using the solvothermal technique with glycol as solvent at 240°C for 12h. The powders were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). XRD was used to elucidate room temperature structures using Rietveld refinement. The powders were pure single pervoskite phase with high crystallinity. FESEM and TEM were used to determine particle size and morphology. The average LiTaO3 grain size was estimated to be < 200nm, and TEM images indicated that LiTaO3 particles had a brick-like morphology. In addition, the effect of the temperature on the LiTaO3 power characterisitics was also detailed studied.


2010 ◽  
Vol 305-306 ◽  
pp. 33-37 ◽  
Author(s):  
S. Lallouche ◽  
M.Y. Debili

This work deals with Al-Cu thin films, deposited onto glass substrates by RF (13.56MHz) magnetron sputtering, and annealed at 773K. The film thickness was approximately the same 3-4µm. They are characterized with respect to microstructure, grain size, microstrain, dislocation density and resistivity versus copper content. Al (Cu) deposits containing 1.8, 7.21, 86.17 and 92.5at%Cu have been investigated. The use of X-ray diffraction analysis and transmission electron microscopy lead to the characterization of different structural features of films deposited at room temperature (< 400K) and after annealing (773K). The resistivity of the films was measured using the four-point probe method. The microstrain profile obtained from XRD thanks to the Williamson-Hall method shows an increase with increasing copper content.


2007 ◽  
Vol 7 (12) ◽  
pp. 4434-4438 ◽  
Author(s):  
Hyoun Woo Kim ◽  
Seung Hyun Shim ◽  
Jong Woo Lee

We reported the fabrication and characterization of MgO nanowires, which were grown by thermal evaporation of the mixture of MgB2 and Sn powders at 800 °C through a vapor-liquid-solid (VLS) process. We characterized as-synthesized MgO nanowires using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Sn nanoparticles were located at the tips of the nanowires, serving as catalyst for the growth of MgO nanowires. The produced nanowires were of cubic MgO structures with diameters in the range of 10–170 nm. The PL measurement with a Gaussian fitting exhibited visible light emission bands centered at 403, 576, and 720 nm.


2007 ◽  
Vol 121-123 ◽  
pp. 127-130
Author(s):  
Juan Liu ◽  
Yue Zhang ◽  
Jun Jie Qi ◽  
Yun Hua Huang ◽  
Xiao Mei Zhang

In-doped ZnO nanodisks were successfully fabricated by thermal evaporation Zn, In2O3 and graphite powder mixture without catalyst. Morphology, structures and components of ZnO nanodisks were investigated by SEM, HRTEM, EDS and X-Ray diffraction. ZnO nanodisks have perfect hexagonal shape, with 1~3μm size and 40~100 nm in thickness. The nanodisks are single-crystalline ZnO with wurtzite structure and In content of nanodisks reaches 2.2%. The growth along [0001] is suppressed leading to the formation of ZnO nanodisks. Room temperature photoluminescence spectra of the nanodisks shows that the UV emission peak blueshifts and becomes broader after doping.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
L. Shekari ◽  
H. Abu Hassan ◽  
S. M. Thahab ◽  
Z. Hassan

In the current research, an easy and inexpensive method is used to synthesize highly crystalline gallium nitride (GaN) nanowires (NWs) on two different substrates [i.e., porous zinc oxide (PZnO) and porous gallium nitride (PGaN)] on Si (111) wafer by thermal evaporation without any catalyst. Microstructural studies by scanning electron microscopy and transmission electron microscope measurements reveal the role of the substrates in the nucleation and alignment of the GaN NWs. Further structural and optical characterizations were performed using high-resolution X-ray diffraction, energy-dispersive X-ray spectroscopy, and photoluminescence spectroscopy. Results indicate that the NWs have a single-crystal hexagonal GaN structure and growth direction in the (0001) plane. The quality and density of GaN NWs grown on different substrates are highly dependent on the lattice mismatch between the NWs and their substrates. Results indicate that NWs grown on PGaN have better quality and higher density compared to NWs on PZnO.


2016 ◽  
Vol 42 ◽  
pp. 47-52
Author(s):  
Dan Dan Huang ◽  
Zhao Dai ◽  
Kun Yang ◽  
Yuan Yuan Chu

The fabrication of gold-loaded magnetite/silica core-shell particles was presented in this paper. First, 250 nm of magnetic Fe3O4 nanoparticles were prepared by solvothermal reaction. Then, the Fe3O4 particles were coated by SiO2, and Au nanoparticles (AuNPs), respectively. The core-shell structure of these microspheres was confirmed by transmission electron microscopy (TEM) and Power X-ray diffraction (XRD). The magnetic property of the core-shell microspheres was investigated at room temperature. The results indicated that the core-shell composites had a well-retained high magnetic intensity, thus it can be easily separated from the mixture in less than a few minutes by simply using a magnet.


2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Jing Wang ◽  
Yang Jiao ◽  
Yang Liu ◽  
Zhenglin Zhang ◽  
Fengyu Qu ◽  
...  

We showed large-scale synthesis of ZnS nanobelts by simply thermal evaporation of ZnS powder in the presence of Au catalysts at 1020°C. Scanning electron microscope (SEM), transmission electron microscope (TEM), and X-ray diffraction (XRD) analyses demonstrated that the as-obtained ZnS nanobelts possess hexagonal wurtzite structures. The nanobelts have lengths ranging from tens to hundreds of micrometers, thicknesses of tens of nanometers, and widths ranging from hundreds of nanometers to the order of micrometers. The growth process was proposed on the basis of known vapor-liquid-solid (VLS) mechanism. Room temperature photoluminescence measurements showed that the as-synthesized ZnS nanostructures had a strong green emission bands at a wavelength of 427 nm, which can be attributed to deep-level emissions induced by defects or impurities.


1999 ◽  
Vol 581 ◽  
Author(s):  
Frederic V. Mikulec ◽  
Moungi G. Bawendi

ABSTRACTWe present a synthesis of colloidal CdTe nanocrystals whose absolute room temperature quantum yields are routinely above 60%. The preparation is based on the trioctylphosphine oxide (TOPO) method reported by Murray, with a more stalbe tellurium precursor now used as the chalcogenide source. The photoluminescence is continuously tunable over the range 590-760 nm and is as narrow as 135 meV (45 nm) FWHM. No deep trap luminescence is detected for the diameter range 4-11 nm. CdTe nanocrystals are characterized by UV/vis absorption, photoluminescence emission, transmission electron microscopy, and powder X-ray diffraction.


2012 ◽  
Vol 535-537 ◽  
pp. 481-485 ◽  
Author(s):  
Mang Jiang ◽  
Jun Hong Duan ◽  
Zhiang Liu

The authors present the results of hetero-epitaxial growth of ultrafine SnO2nanowires on ZnS nanobelt substrates by a simple thermal evaporation method. ZnS/SnO2hetero-nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS), transmission electron microscopy (TEM) to obtain the morphology and structural information. Comparing with ZnS nanobelts and SnO2nanowires respectively, the optical properties of ZnS/SnO2hetero-nanostructures are studied by Raman scattering and photoluminescence (PL) spectroscopy at room temperature.


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