Electron microscopy study of tin whisker growth

2003 ◽  
Vol 18 (3) ◽  
pp. 585-593 ◽  
Author(s):  
J. B. LeBret ◽  
M. G. Norton
Keyword(s):  
Electron Microscopy ◽  
Whisker Growth ◽  
Intermetallic Phase ◽  
Microscopy Study ◽  
Growth Direction ◽  
Electron Microscopy Study ◽  
Tin Whiskers ◽  
Tin Whisker ◽  
Compressive Stresses ◽  
Whisker Morphology

The growth of tin whiskers formed on sputtered tin layers deposited on brass was studied using electron microscopy. The occurrence of whiskers appeared to be largely independent of the macroscopic stress state in the film; rather it was microscopic compressive stresses arising from the formation of an intermetallic phase that appeared to be the necessary precursor. Whisker morphology was a result of whether nucleation had occurred on single grains or on multiple grains. In the latter case, the whiskers had a fluted or striated surface. The formation of whiskers on electron transparent samples was demonstrated. These samples showed the whiskers were monocrystalline and defect free, and that the growth direction could be determined.

HIGH RESOLUTION ELECTRON MICROSCOPY STUDY OF A NOVEL NANOSTRUCTURE OF TITANIUM DIOXIDE

2004 ◽  
Vol 03 (06) ◽  
pp. 693-698
Author(s):  
G. B. MA ◽  
J. M. ZHU ◽  
N.-B. MING
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Microscopy Study ◽  
Growth Direction ◽  
Electron Microscopy Study ◽  
Sonochemical Method ◽  
Secondary Particles ◽  
Resolution Electron ◽  
Almost All

Chestnut-bur-like assemblies composed of rutile TiO 2 acicular nanocrystals with radial coagulation in all directions are synthesized by a sonochemical method. High resolution electron microscopy investigations indicate that the growth direction of the acicular nanocrystals is along rutile TiO 2 [001], bending features almost all of these nanocrystals, and misoriented attachment of them results in chestnut-bur-like secondary particles.

Electron Microscopy Study of Exotic Nanostructures of Cadmium Sulfide

2005 ◽  
Vol 11 (2) ◽  
pp. 116-123 ◽  
Author(s):  
Lifeng Dong ◽  
Jun Jiao
Keyword(s):  
Electron Microscopy ◽  
Thermal Evaporation ◽  
Microscopy Study ◽  
Growth Direction ◽  
Electron Microscopy Study ◽  
Growth Mechanisms ◽  
Thermal Evaporation Method ◽  
Cds Nanorods ◽  
Cds Nanostructures ◽  
Morphological Differences

In this article, two simple methods, evaporation-condensation and catalytic thermal evaporation, were used to investigate the synthesis of CdS nanostructures for nanoscale optoelectronic applications. To understand their growth mechanisms, various electron microscopy and microanalysis techniques were utilized in characterizing their morphologies, internal structures, growth directions and elemental compositions. The electron microscopy study reveals that when using the evaporation-condensation method, branched CdS nanorods and self-assembled arrays of CdS nanorods were synthesized at 800°C and 1000°C, respectively. Instead of morphological differences, both types of CdS nanorods grew along the [0001] direction. However, when using the catalytic thermal evaporation method (Au as the catalyst), patterned CdS nanowires and nanobelts were formed at the temperature region of 500–600°C and 600–750°C, respectively. Their growth direction was along the direction [1010] instead of [0001]. Based on the microscopy and microanalysis results, we propose some growth mechanisms in relation to the growth processes of those exotic CdS nanostructures.

A high-resolution transmission electron microscopy study of defects in γ-Al2O3 nanorods

2007 ◽  
Vol 22 (3) ◽  
pp. 595-602 ◽  
Author(s):  
W.F. Li ◽  
X.L. Ma ◽  
Y. Li ◽  
W.S. Zhang ◽  
Z.D. Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Arc Discharge ◽  
Microscopy Study ◽  
Growth Direction ◽  
Electron Microscopy Study ◽  
Experimental Result ◽  
Transmission Electron ◽  
Discharge Method

Surface and planar defect structures of γ-Al2O3 nanorods synthesized by the arc-discharge method were studied by means of high-resolution transmission electron microscopy and image simulation. Our investigation showed that there was a high number density of twins in the nanorods. We suggested a possible configuration of {111} twins in γ-Al2O3, and this model fit our experimental result well. In some nanorods, the ordering of nanotwins gave rise to a local hexagonal-like structure. The twinned nanorods were usually enclosed by {100} and {111} facets, and their growth direction was changed from 〈110〉 into 〈111〉. The surface structures of the nanorods confirmed that the {111}-type surface should be more stable.

Growth mechanism of titanium monoxide TiOxon a reduced calcium titanate CaTi2O4surface

2015 ◽  
Vol 48 (6) ◽  
pp. 1889-1895 ◽  
Author(s):  
Cong Guo ◽  
Huaping Sheng ◽  
Yurong Ma ◽  
Lei Jin ◽  
Shuangfeng Jia ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Growth Mechanism ◽  
Electron Backscatter Diffraction ◽  
Microscopy Study ◽  
Growth Direction ◽  
Electron Microscopy Study ◽  
Calcium Titanate ◽  
Salt Flux ◽  
Titanium Monoxide ◽  
Crystallographic Orientation Relationship

This paper presents an electron microscopy study of reduced calcium titanate crystals (CaTi2O4) and the growth mechanism of titanium monoxide TiOxon a CaTi2O4surface. Large high-quality CaTi2O4crystals were prepared using the molten salt flux method. The crystallographic directions and the growth direction of the CaTi2O4crystalline needles were confirmed by electron backscatter diffraction and Kikuchi pattern analysis. The low-angle grain boundaries in CaTi2O4and the crystallographic orientation relationship between CaTi2O4and TiOxwere investigated using high-resolution transmission electron microscopy. It is found that both the low-angle boundaries and the amorphous area may play a key role during the growth process of titanium monoxide TiOx. The results presented here contribute to a better understanding of the detailed growth mechanism of TiOxon a CaTi2O4surface.

Factors influencing adhesive bonding at the bone/implant interface

1992 ◽  
Vol 50 (2) ◽  
pp. 1114-1115
Author(s):  
Julie A. Martini ◽  
Robert H. Doremus
Keyword(s):  
Electron Microscopy ◽  
Adhesive Bonding ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Bone Implant ◽  
Factors Influencing ◽  
Lr White ◽  
Transmission Electron ◽  
New Zealand White Rabbits ◽  
Scanning Electron

Tracy and Doremus have demonstrated chemical bonding between bone and hydroxylapatite with transmission electron microscopy. Now researchers ponder how to improve upon this bond in turn improving the life expectancy and biocompatibility of implantable orthopedic devices.This report focuses on a study of the- chemical influences on the interfacial integrity and strength. Pure hydroxylapatite (HAP), magnesium doped HAP, strontium doped HAP, bioglass and medical grade titanium cylinders were implanted into the tibial cortices of New Zealand white rabbits. After 12 weeks, the implants were retrieved for a scanning electron microscopy study coupled with energy dispersive spectroscopy.Following sacrifice and careful retrieval, the samples were dehydrated through a graduated series starting with 50% ethanol and continuing through 60, 70, 80, 90, 95, and 100% ethanol over a period of two days. The samples were embedded in LR White. Again a graduated series was used with solutions of 50, 75 and 100% LR White diluted in ethanol.

Transmission Electron Microscopy study of Bi-based superconducting phases

1990 ◽  
Vol 48 (4) ◽  
pp. 50-51
Author(s):  
J.G. Wen ◽  
K.K. Fung
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Crystals ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Space Groups ◽  
Superconducting Phases ◽  
Ceramic Samples ◽  
Transmission Electron ◽  
Modulated Structures

Bi-based superconducting phases have been found to be members of a structural series represented by Bi2Sr2Can−1Cun−1On+4, n=1,2,3, and are referred to as 2201, 2212, 2223 phases. All these phases are incommensurate modulated structures. The super space groups are P2/b, NBbmb 2201, 2212 phases respectively. Pb-doped ceramic samples and single crystals and Y-doped single crystals have been studied by transmission electron microscopy.Modulated structures of all Bi-based superconducting phases are in b-c plane, therefore, it is the best way to determine modulated structure and c parameter in diffraction pattern. FIG. 1,2,3 show diffraction patterns of three kinds of modulations in Pb-doped ceramic samples. Energy dispersive X-ray analysis (EDAX) confirms the presence of Pb in the three modulated structures. Parameters c are 3 0.06, 38.29, 30.24Å, ie 2212, 2223, 2212 phases for FIG. 1,2,3 respectively. Their average space groups are all Bbmb.

Electron microscopy study of microtexture in Cu-Al-Ni shape memory alloys processed by powder metallurgy

2003 ◽  
Vol 112 ◽  
pp. 615-618 ◽  
Author(s):  
P. P. Rodriguez ◽  
J. San Jean ◽  
A. Iza-Mendia ◽  
V. Recarte ◽  
J. J. Pérez-Landazabal ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Powder Metallurgy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Microscopy Study ◽  
Electron Microscopy Study
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