scholarly journals Imaging the Polymorphic Transformation in a Single Cu6Sn5 Grain in a Solder Joint

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2229 ◽  
Author(s):  
Flora Somidin ◽  
Hiroshi Maeno ◽  
Xuan Tran ◽  
Stuart D. McDonald ◽  
Mohd Mohd Salleh ◽  
...  
Keyword(s):  
Solder Joint ◽  
Polymorphic Transformation ◽  
Structural Evolution ◽  
Real Space ◽  
Transformation Behavior ◽  
New Approach ◽  
Transmission Electron ◽  
Contrast Pattern ◽  
In Situ Observations

In-situ observations of the polymorphic transformation in a single targeted Cu6Sn5 grain constrained between Sn-0.7 wt % Cu solder and Cu-Cu3Sn phases and the associated structural evolution during a solid-state thermal cycle were achieved via a high-voltage transmission electron microscope (HV-TEM) technique. Here, we show that the monoclinic η′-Cu6Sn5 superlattice reflections appear in the hexagonal η-Cu6Sn5 diffraction pattern upon cooling to isothermal 140 °C from 210 °C. The in-situ real space imaging shows that the η′-Cu6Sn5 contrast pattern is initiated at the grain boundary. This method demonstrates a new approach for further understanding the polymorphic transformation behavior on a real solder joint.

In situ observations of electromigration induced void behavior

1995 ◽  
Vol 53 ◽  
pp. 244-245
Author(s):  
T. Marieb ◽  
J. C. Bravman ◽  
P. Flinn ◽  
D. Gardner ◽  
M. Madden
Keyword(s):  
Electron Microscopy ◽  
Void Nucleation ◽  
Plan View ◽  
Transmission Electron ◽  
Nucleation Sites ◽  
Microelectronics Industry ◽  
In Situ Observations ◽  
Backscatter Electron Detector ◽  
Voltage Scanning

Electromigration and stress voiding have been active areas of research in the microelectronics industry for many years. While accelerated testing of these phenomena has been performed for the last 25 years[1-2], only recently has the introduction of high voltage scanning electron microscopy (HVSEM) made possible in situ testing of realistic, passivated, full thickness samples at high resolution.With a combination of in situ HVSEM and post-testing transmission electron microscopy (TEM) , electromigration void nucleation sites in both normal polycrystalline and near-bamboo pure Al were investigated. The effect of the microstructure of the lines on the void motion was also studied.The HVSEM used was a slightly modified JEOL 1200 EX II scanning TEM with a backscatter electron detector placed above the sample[3]. To observe electromigration in situ the sample was heated and the line had current supplied to it to accelerate the voiding process. After testing lines were prepared for TEM by employing the plan-view wedge technique [6].

scholarly journals Applications of in situ electron microscopy in oxygen electrocatalysis

2022 ◽  
Author(s):  
Zhi-Peng Wu ◽  
Hui Zhang ◽  
Cailing Chen ◽  
Guanxing Li ◽  
Yu Han
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Degradation Mechanism ◽  
Structural Evolution ◽  
Reduction Reaction ◽  
Future Research ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
In Situ Electron Microscopy

Oxygen electrocatalysis involving the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) plays a vital role in cutting-edge energy conversion and storage technologies. In situ studies of the evolution of catalysts during oxygen electrocatalysis can provide important insights into their structure - activity relationships and stabilities under working conditions. Among the various in situ characterization tools available, in situ electron microscopy has the unique ability to perform structural and compositional analyzes with high spatial resolution. In this review, we present the latest developments in in situ and quasi-in situ electron microscopic techniques, including identical location electron microscopy, in situ liquid cell (scanning) transmission electron microscopy and in situ environmental transmission electron microscopy, and elaborate their applications in the ORR and OER. Our discussion centers on the degradation mechanism, structural evolution and structure - performance correlations of electrocatalysts. Finally, we summarize the earlier discussions and share our perspectives on the current challenges and future research directions of using in situ electron microscopy to explore oxygen electrocatalysis and related processes.

scholarly journals In situ observation of cracking and self-healing of solid electrolyte interphases during lithium deposition

2020 ◽  
Author(s):  
Tingting Yang ◽  
Hui Li ◽  
Yongfu Tang ◽  
Jingzhao Chen ◽  
Hongjun Ye ◽  
...  
Keyword(s):  
Solid Electrolyte ◽  
Solid Electrolyte Interphase ◽  
Dendrite Growth ◽  
In Situ Observation ◽  
Self Healing ◽  
Directional Growth ◽  
Transmission Electron ◽  
In Situ Observations ◽  
Li Batteries

Abstract The growth of lithium (Li) whiskers is detrimental to Li batteries. However, it remains a challenge to directly track Li whisker growth. Here we report in situ observations of electrochemically induced Li deposition under a CO2 atmosphere inside an environmental transmission electron microscope. We find that the morphology of individual Li deposits is strongly influenced by the competing processes of cracking and self-healing of the solid electrolyte interphase (SEI). When cracking overwhelms self-healing, the directional growth of Li whiskers predominates. In contrast, when self-healing dominates over cracking, the isotropic growth of round Li particles prevails. The Li deposition rate and SEI constituent can be tuned to control the Li morphologies. We reveal a new “weak-spot” mode of Li dendrite growth, which is attributed to the operation of the Bardeen-Herring growth mechanism in the whisker’s cross section. This work has implications for the control of Li dendrite growth in Li batteries.

Progress in environmental high-voltage transmission electron microscopy for nanomaterials

2020 ◽  
Vol 378 (2186) ◽  
pp. 20190602
Author(s):  
Nobuo Tanaka ◽  
Takeshi Fujita ◽  
Yoshimasa Takahashi ◽  
Jun Yamasaki ◽  
Kazuyoshi Murata ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Voltage ◽  
High Energy ◽  
Transmission Electron ◽  
Recent Developments ◽  
In Situ Observations ◽  
High Voltage Transmission ◽  
And Function

A new environmental high-voltage transmission electron microscope (E-HVEM) was developed by Nagoya University in collaboration with JEOL Ltd. An open-type environmental cell was employed to enable in-situ observations of chemical reactions on catalyst particles as well as mechanical deformation in gaseous conditions. One of the reasons for success was the application of high-voltage transmission electron microscopy to environmental (in-situ) observations in the gas atmosphere because of high transmission of electrons through gas layers and thick samples. Knock-on damages to samples by high-energy electrons were carefully considered. In this paper, we describe the detailed design of the E-HVEM, recent developments and various applications. This article is part of a discussion meeting issue ‘Dynamic in situ microscopy relating structure and function'.

The effect of carbon element on optical properties of n-doped Ge on silicon substrate

2018 ◽  
Vol 32 (20) ◽  
pp. 1850224
Author(s):  
Thi Kim Phuong Luong
Keyword(s):  
High Energy ◽  
New Approach ◽  
Transmission Electron ◽  
Active Concentration ◽  
Ge Matrix ◽  
N Doping ◽  
Dopant Atoms ◽  
Low Solubility

Highly n-doped Ge on Si has been demonstrated to be a promising candidate for the compatible light source with silicon technology. In the in-situ n-doping process of Ge epilayers, the active concentration is limited below [Formula: see text] due to low solubility of dopant element in Ge matrix. Many dopant atoms are incorporated in the interstitial sites instead of substitution sites. We present a new approach to increase the electron concentration by adding carbon elements into P-doped Ge epilayers. A gain of PL intensity has been obtained with a factor of 2. The crystalline quality of the Ge film is also investigated owing to using a reflection high-energy electron diffraction (RHEED) apparatus and high-resolution transmission electron microscopy (HR-TEM). Phosphorus dopant is incorporated into Ge epilayers from specific GaP solid source.

scholarly journals Achieving Secondary Dispersion of Modified Nanoparticles by Hot-Stretching to Enhance Dielectric and Mechanical Properties of Polyarylene Ether Nitrile Composites

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 1006 ◽  
Author(s):  
Yong You ◽  
Ling Tu ◽  
Yajie Wang ◽  
Lifen Tong ◽  
Renbo Wei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Temperature Stability ◽  
Nanocomposite Films ◽  
Dielectric Films ◽  
New Approach ◽  
Polyarylene Ether Nitrile ◽  
Transmission Electron ◽  
Dielectric Performance ◽  
Dielectric And Mechanical Properties

Enhanced dielectric and mechanical properties of polyarylene ether nitrile (PEN) are obtained through secondary dispersion of polyaniline functionalized barium titanate (PANI-f-BT) by hot-stretching. PANI-f-BT nanoparticles with different PANI content are successfully prepared via in-situ aniline polymerization technology. The transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopic instrument (XPS) and Thermogravimetric analysis (TGA) results confirm that the PANI layers uniformly enclose on the surface of BaTiO3 nanoparticles. These nanoparticles are used as functional fillers to compound with PEN (PEN/PANI-f-BT) for studying its effect on the mechanical and dielectric performance of the obtained composites. In addition, the nanocomposites are uniaxial hot-stretched by 50% and 100% at 280 °C to obtain the oriented nanocomposite films. The results exhibit that the PANI-f-BT nanoparticles present good compatibility and dispersion in the PEN matrix, and the hot-stretching endows the second dispersion of PANI-f-BT in PEN resulting in enhanced mechanical properties, crystallinity and permittivity-temperature stability of the nanocomposites. The excellent performances of the nanocomposites indicate that a new approach for preparing high-temperature-resistant dielectric films is provided.

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