The grain refinement mechanism of electrodeposited copper

2009 ◽  
Vol 24 (10) ◽  
pp. 3226-3236 ◽  
Author(s):  
Guoyong Wang ◽  
Zhonghao Jiang ◽  
Jianshe Lian ◽  
Qing Jiang

Microstructure features of five electrodeposited coppers with different grain sizes were systematically characterized by using transmission electron microscopy (TEM) observations and x-ray diffraction (XRD) analysis. Based on the experimental observations, two mechanisms for the grain refinement in electrodeposited copper were identified: (i) twin–twin intersection can directly create grains with large-angle boundaries as small as 10 nm and (ii) grains can also be refined via formation of dislocation cells, transformation of dislocation cell walls into sub-boundaries with small misorientations, and evolution of sub-boundaries into highly misoriented grain boundaries. Besides, dislocations are also effective to cut twin lamellas into pieces and make twin boundaries curved and round.

2007 ◽  
Vol 124-126 ◽  
pp. 1229-1232 ◽  
Author(s):  
Myoung Seok Sung ◽  
Yoon Bok Lee ◽  
Yong Jin Kim ◽  
Yang Do Kim

Cadmium selenide(CdSe) nanoparticles were prepared in the aqueous solution containing isopropyl alcohol by the ultrasonic irradiation at room temperature. The cadmium chloride (CdCl2) and sodium selenosulfate (Na2SeSO3) were used as the cadmium and selenium source, respectively. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), UV-Vis absorption spectra and PL spectra were used to characterize the CdSe nanoparticles. XRD analysis revealed the formation of cubic structure CdSe. TEM images showed aggregated CdSe nanoparticles with the size of nanometer scale. Average size of CdSe nanoparticles were about 3.9, 5.0 and 5.1nm with sonication time of 6, 30 and 40 minutes, respectively. The surface emission became less intensive and shifted to red with increasing irradiation time. This paper presents the effects of ultrasonic on the formation of CdSe nanoparticles and its characteristics.


2008 ◽  
Vol 8 (5) ◽  
pp. 2713-2718
Author(s):  
Y. H. Lu ◽  
K. Chu ◽  
Y. G. Shen

The nanostructures and mechanical properties of nanocomposite nc-TiN/a-(TiB2, BN) and nanostructured multilayers nc-TiN/a-TiBN were investigated using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), microindentation, and stress measurements. It was found that the monolayer Ti-B-N thin films consisted of nanometer-sized crystalline (nc-) Ti(N, B) embedded into amorphous (a-) (TiB2, BN) matrix. When B content was below ∼16 at.%, two different-sized nanocrystallites with mean grain sizes of ∼3 and 9 nm respectively were embedded in a-TiB2. With increasing B incorporation (>∼27 at.%), more uniform nanograins was embedded a-(TiB2, BN). Incorporation of B not only decreased the size of nanocrystallites, but also gave rise to twinning deformation in nanocrystallites. A maximum hardness of ∼44 GPa was achieved at B content of 19 at.%. It was also found that the nanostructure and mechanical behaviors of nc-TiN/a-TiBN multilayers was dependent on the modulation length (bilayer thickness Λ). Decrease of Λ made the preferred orientation of nc-TiN gradually transform from (200) to (111). A maximum hardness of ∼30 GPa was achieved at Λ = 1.8 nm. Deflection from this Λ value decreased hardness. By contrast, the residual compressive stress value monotonically increased with decrease of Λ. The enhancement of the hardness was due to the coherent stresses and the structural barriers to dislocation motion in the interface.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Manoj Pudukudy ◽  
Zahira Yaakob

α-Mn2O3 microspheres with high phase purity, crystallinity, and surface area were synthesized by the thermal decomposition of precipitated MnCO3 microspheres without the use of any structure directing agents and tedious reaction conditions. The prepared Mn2O3 microspheres were characterized by Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) and photoluminescence (PL) studies. The complete thermal transformation of MnCO3 to Mn2O3 was clearly shown by the FTIR and XRD analysis. The electron microscopic images clearly confirmed the microsphere-like morphology of the products with some structural deformation for the calcined Mn2O3 sample. The mesoporous texture generated from the interaggregation of subnanoparticles in the microstructures is visibly evident from the TEM and BET studies. Moreover, the Mn2O3 microstructures showed a moderate photocatalytic activity for the degradation of methylene blue dye pollutant under UV light irradiation, using air as the potential oxidizing agent.


Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 85
Author(s):  
Patnamsetty Chidanandha Nagajyothi ◽  
Kisoo Yoo ◽  
Rajavaram Ramaraghavulu ◽  
Jaesool Shim

In this study, manganese tungstate (MW) and MW/graphene oxide (GO) composites were prepared by a facile hydrothermal synthesis at pH values of 7 and 12. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy were used for the structural, compositional, and morphological characterization of the nanoparticles (NPs). The XRD analysis revealed that the formation of monoclinic MnWO4 did not have impurities. The SEM and TEM analyses showed that the synthesized NPs were rod-shaped and well-distributed on the GO. The as-synthesized samples can be used as electrocatalysts for the urea oxidation reaction (UOR). The MW@GO-12 electrocatalyst exhibited higher current density values compared to other electrocatalysts. This study provides a new platform for synthesizing inexpensive nanocomposites as promising electrocatalysts for energy storage and conversion applications.


2017 ◽  
Vol 31 (32) ◽  
pp. 1750297 ◽  
Author(s):  
M. Karimipour ◽  
M. Bagheri ◽  
M. Molaei

Stability of Ag2S@ZnS QDs in water is a crucial concern for their application in biology. In this work, both physical sustainability and emission stability of Ag2S QDs were enhanced using parameter optimization of a pulsed microwave irradiation (MI) method up to 105 days after their preparation. UV–Vis and photoluminescence spectroscopies depicted an absorption and emission about 817 nm and 878 nm, respectively. X-ray diffraction (XRD) analysis showed a growth of Ag2S acanthite phase. Transmission Electron Microscopy (TEM) images revealed a clear formation of Ag2S@ZnS core–shell structure.


2010 ◽  
Vol 160-162 ◽  
pp. 1301-1308 ◽  
Author(s):  
Jun Yuan ◽  
Yuan Wu ◽  
Qi Xin Zheng ◽  
Xiao Lin Xie

Hydroxylapatite(HAP) nano-whiskers are prepared by reaction-precipitation in the submerged circulative impinging stream reactor(SCISR), with (NH4)2HPO4 and Ca(NO3)2 as the reagents; and the products are characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The results TEM measured indicate that the product prepared under typical operation conditions is average-sized 15nm and 50-70nm long. Multiply repeated experiments illustrates that, because of the excellent performance of the reactor, the preparation process can be easily controlled to yield nano rod/whisker hydroxylapatite with very narrow size distribution.


1992 ◽  
Vol 7 (4) ◽  
pp. 888-893 ◽  
Author(s):  
M. Sherif El-Eskandarany ◽  
K. Sumiyama ◽  
K. Aoki ◽  
K. Suzuki

Nonequilibrium titanium-nitride alloy powders have been fabricated by a high energetic ball mill under nitrogen gas flow at room temperature and characterized by means of x-ray diffraction, scanning electron microscopy, transmission electron microscopy, and differential scanning calorimetry. Initial hcp titanium is completely transformed to nonequilibrium-fcc Ti–N after 720 ks of the milling time. The fcc Ti–N phase is stable at relatively low temperature and transforms at 855 K to Ti2N and δ phases. At the final stage of milling, the particle- and grain-sizes of alloy powders are 1 mm and 5 nm, respectively, and the lattice parameter is 0.419 nm.


1998 ◽  
Vol 548 ◽  
Author(s):  
T. D. Tran ◽  
X. Y. Song ◽  
K. Kinoshita

ABSTRACTThe microstructures of lithiated synthetic graphite and carbon black were studied by high- resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) analysis. Information about the crystal structure of carbon containing various Li compositions can provide useful insights to our understanding of the Li storage mechanism in carbonaceous materials. Samples with compositions of Li0.93C6or Li0.45C6 were found to contain both stage-one and stage-two compounds. These observations are consistent with XRD data. The changes in sample microstructure as the results of lithiation and exposure to electron irradiation were observed by TEM and recorded over several minutes in the microscope environment. Selected area electron diffraction patterns indicated that the lithiated samples quickly changed composition to LiC 24, which appeared to dominate during the brief analysis period. The layer planes in the lattice image of a disordered carbon black after Li insertion are poorly defined, and changes in the microstructure of these lithiated carbons was not readily apparent. Observations on these lithium intercalation compounds as well as the limitation of the experimental procedure will be presented.


2013 ◽  
Vol 873 ◽  
pp. 164-167
Author(s):  
Xiao Ming Fu

ZrO2 nanoparticles with a diameter range of less than 10 nm are successfully synthesized with zirconium nitrate as zirconium source and stronger ammonia water as precipitant at 210 °C for 48 h via the easy hydrothermal method. The phase, the morphologies and optical absorption properties of the samples have been characterized and analyzed by X-ray diffraction (XRD), field-emission transmission electron microscopy (TEM) and ultraviolet-visible absorption spectroscopy (UV-VIS), respectively. XRD analysis shows that the phase of as obtained samples is ZrO2. TEM analysis confirms that using stronger ammonia water as precipitant instead of NaOH and the increase of the reaction temperature are in favor of the synthesis of ZrO2 nanoparticles. And UV-VIS measurements show that ZrO2 nanoparticles have a good optical absorption property.


2005 ◽  
Vol 498-499 ◽  
pp. 636-641 ◽  
Author(s):  
P. Hidalgo Falla ◽  
H.E.M. Peres ◽  
Douglas Gouvêa ◽  
F.J. Ramirez-Fernandez

In this work tin dioxide (SnO2) doped with nickel is studied with the aim of develop integrated gas sensors for some important pollution gases into environment, principally sulphur dioxide (SO2). SnO2 powders doped with Nickel were prepared by Pechini`s method [1] and characterized morphologically by X-Ray diffraction, measurement of specific surface area (SBET) and transmission electron microscopy (TEM), which revealed grain sizes around 5 to 10 nm. Gas sensors were fabricated by spin-coating deposition of Ni doped SnO2 films over alumina substrate with gold contacts. Electrical resistance of such device is characterized, at room temperature, as function of SO2 concentration into environment, showing a sensitivity around 0.0058 ppm-1 for relative resistance variation, with good linearity for SO2 concentrations up to 30 ppm. Also, FTIR analysis shows the desorption of SO2 from SnO2 surface, after cleaning into fresh air.


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