Current-induced growth of P-rich phase at electroless nickel/Sn interface

2009 ◽  
Vol 24 (9) ◽  
pp. 2767-2774 ◽  
Author(s):  
Qiliang Yang ◽  
Panju Shang ◽  
Jing D. Guo ◽  
Zhiquan Liu ◽  
Jian-Ku Shang
Keyword(s):  
Electroless Nickel ◽  
Growth Patterns ◽  
Columnar Growth ◽  
Rich Phase ◽  
Reaction Fronts ◽  
Current Stressing ◽  
Transmission Electron ◽  
The Difference ◽  
Electroless Ni

The role of high current stressing during growth of the P-rich phase at the electroless Ni/Sn interface was examined by transmission electron microscopy. Prior to current stressing, two layers of Ni12P5, columnar Ni12P5 and noncolumnar Ni12P5, were formed after soldering. Upon electric stressing, the two layers of P-rich phase showed opposite growth patterns at the two opposing electrode interfaces. At the cathode, columnar growth of the P-rich phase was greatly enhanced while growth of the noncolumnar layer was inhibited. By contrast, the opposite was found at the anode where the current stressing promoted the noncolumnar growth but suppressed the growth of the columnar layer. Such a strong polarity effect resulted from directional electromigration of the key reaction species, nickel, to and from the interfacial reaction fronts. As a result of the difference in reaction mechanism, overall growth of the P-rich phase was much faster at the cathode during current stressing.

scholarly journals Quantitative Evaluation of Human Lens Epithelial Cell Viability and Cytolysis by Distilled Water Ex Vivo

2021 ◽  
Author(s):  
Wen-Wen Zhang ◽  
Rong-Pei Zhang ◽  
Ya-Jun Liu ◽  
Zi-Fang He ◽  
Si Zhang ◽  
...  
Keyword(s):  
Cell Viability ◽  
Ex Vivo ◽  
Lens Epithelial Cell ◽  
Human Lens ◽  
Distilled Water ◽  
Histopathological Changes ◽  
Human Lens Epithelial Cell ◽  
Transmission Electron ◽  
The Difference

Abstract Purpose: To investigate the role of distilled water (DW) in isolated human lens epithelial cells (LECs) viability and lysis ex vivo.Methods: After immersion in DW or balanced salt solution (BSS) for 1-, 2-, and 3-minutes, respectively, the cell viability of LECs was quantitatively evaluated. In addition, the capsule samples soaked in DW or BSS for 1-, 2-, and 3-minutes were combined with rinse for 1 minute to analyze the difference of LECs shedding percentage in each subgroup. The histopathological changes of the samples after treating were observed.Results: The percentage of LECs shed in DW immersion combined with rinse was significantly higher than in DW immersion alone (p all <0.001). In the subgroup soaked in DW for 3 minutes, the death number, mortality, and the percentage of cell shedding of LECs was the most (p all <0.001). The histopathological changes showed that the cell destruction in the DW subgroup for 1-, 2-, and 3-minutes, and the transmission electron microscope results showed that the cells were partially detached from the capsule in the DW 3 minutes subgroup.Conclusions: Soaking in the DW can cause LECs death, and DW immersion combined with rinse was an effective method to remove LECs. The histopathology changes of treated DW suggested cellular necrosis was one type of LECs death mechanism.

Fracture of SnBi/Ni(P) interfaces

2005 ◽  
Vol 20 (4) ◽  
pp. 818-826 ◽  
Author(s):  
P.L. Liu ◽  
J.K. Shang
Keyword(s):  
Fracture Mechanism ◽  
Fracture Resistance ◽  
Potential Role ◽  
Substrate Interface ◽  
Interfacial Segregation ◽  
The Difference ◽  
Cu Interconnect ◽  
Electroless Ni ◽  
Bi Segregation

Fracture resistance of the interface between electroless Ni(P) and the eutectic SnBi solder alloy was examined in the as-reflowed and aged conditions, to investigate the potential role of Ni in inhibiting interfacial segregation of Bi in SnBi–Cu interconnect. In the as-reflowed condition, the fracture resistance of the SnBi/Ni(P) interface was about the same as that of the SnBi/Cu interface. Upon aging at 120 °C for 7 days the fracture resistance of the SnBi/Ni(P) interface was much higher than that of the SnBi/Cu interface. Such a difference was shown to result from the difference in fracture mechanism as the crack remained along the solder–intermetallic interface in the aged SnBi–Ni interconnect but propagated along the intermetallic–substrate interface in the aged SnBi–Cu interconnect. While fracture of the intermetallic–substrate interface in SnBi–Cu interconnect was due to Bi segregation onto that interface, no Bi was detected at the intermetallic-substrate interface in SnBi–Ni interconnects, implying that Ni(P) was effective in inhibiting the interfacial segregation of Bi.

Discrete angle rotations of Bi nanoparticles embedded in a Ga matrix

Open Physics ◽  
2010 ◽  
Vol 8 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Avraham Be’er ◽  
Richard Kofman ◽  
Yossi Lereah
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Time Resolved ◽  
Transmission Electron ◽  
The Difference ◽  
First Time ◽  
Microscopy Images ◽  
Bi Nanoparticles

AbstractSpontaneous instabilities of nanoparticles are known to be influenced by the temperature, and strongly depend on the particle size. However, it is not clear what is the role of the surrounding material that is in contact with the particle. Here we report on the difference between spontaneous rotations of Bi nanoparticles embedded in amorphous SiO and those embedded in liquid Ga. The phenomenon was studied quantitatively by time resolved transmission electron microscopy using Fourier Transform analysis of highresolution electron microscopy images. While rotations of Bi nanoparticles embedded in amorphous SiO occur by all angles, the rotations of Bi nanoparticles embedded in liquid Ga occur by discrete angles. Our results point quantitatively, for the first time, to the role and importance of the contacting surrounding surface during the rotation of nanoparticles.

Electroless Ni plating solutions for reproducible black pad analyses.

2013 ◽  
Vol 2013 (1) ◽  
pp. 000397-000401
Author(s):  
K.H. Kim ◽  
Jin Yu
Keyword(s):  
Electron Microscopy ◽  
Large Scale ◽  
Electroless Nickel ◽  
Complexing Agent ◽  
Chemical Compositions ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Black Pad ◽  
Electroless Ni ◽  
Scanning Electron

A large-scale black pad of electroless nickel (EN) plated films were reproduced using pure chemicals: NiCl2·6H2O as the Ni source, NaH2PO2·H2O as the reducing agent, CH3COONa·3H2O and aminoacetate as the complexing agent and the buffer, respectively, and thiourea as the stabilizer. Plating baths with varying constituent compositions were investigated, and chemical compositions most suitable to the black pad study were sought. Cross-sectional scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses showed that the nickel-phosphorus (Ni-P) film made out of the #5 bath best demonstrated the typical characteristics of the black pad phenomenon after the immersion gold (IG) process. Additions of a low level of Thiourea (0.6mg/L), slightly larger amounts of glycine (1∼1.25x) and the complexing agent (1.25x) were suggested from the standpoint of the black pad formation of Ni-P films.

Influence of Cell Wall Composition on the Fossilisation of Bacteria and the Implications for the Search for Early Life Forms

1997 ◽  
Vol 161 ◽  
pp. 491-504 ◽  
Author(s):  
Frances Westall
Keyword(s):  
Cell Wall ◽  
Life Forms ◽  
Cation Binding ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Transmission Electron ◽  
Hydrothermal Sediments ◽  
Identification Of Bacteria ◽  
The Difference

AbstractThe oldest cell-like structures on Earth are preserved in silicified lagoonal, shallow sea or hydrothermal sediments, such as some Archean formations in Western Australia and South Africa. Previous studies concentrated on the search for organic fossils in Archean rocks. Observations of silicified bacteria (as silica minerals) are scarce for both the Precambrian and the Phanerozoic, but reports of mineral bacteria finds, in general, are increasing. The problems associated with the identification of authentic fossil bacteria and, if possible, closer identification of bacteria type can, in part, be overcome by experimental fossilisation studies. These have shown that not all bacteria fossilise in the same way and, indeed, some seem to be very resistent to fossilisation. This paper deals with a transmission electron microscope investigation of the silicification of four species of bacteria commonly found in the environment. The Gram positiveBacillus laterosporusand its spore produced a robust, durable crust upon silicification, whereas the Gram negativePseudomonas fluorescens, Ps. vesicularis, andPs. acidovoranspresented delicately preserved walls. The greater amount of peptidoglycan, containing abundant metal cation binding sites, in the cell wall of the Gram positive bacterium, probably accounts for the difference in the mode of fossilisation. The Gram positive bacteria are, therefore, probably most likely to be preserved in the terrestrial and extraterrestrial rock record.

Destruction of Actin Filaments by Osmium Tetroxide

1977 ◽  
Vol 35 ◽  
pp. 466-467
Author(s):  
P. Maupin-Szamier ◽  
T. D. Pollard
Keyword(s):  
Actin Filaments ◽  
Time Course ◽  
Osmium Tetroxide ◽  
Rabbit Muscle ◽  
Muscle Actin ◽  
Sodium Phosphate Buffer ◽  
Transmission Electron ◽  
The Difference ◽  
Rates Of Decay ◽  
Short Time

We have studied the destruction of rabbit muscle actin filaments by osmium tetroxide (OSO4) to develop methods which will preserve the structure of actin filaments during preparation for transmission electron microscopy.Negatively stained F-actin, which appears as smooth, gently curved filaments in control samples (Fig. 1a), acquire an angular, distorted profile and break into progressively shorter pieces after exposure to OSO4 (Fig. 1b,c). We followed the time course of the reaction with viscometry since it is a simple, quantitative method to assess filament integrity. The difference in rates of decay in viscosity of polymerized actin solutions after the addition of four concentrations of OSO4 is illustrated in Fig. 2. Viscometry indicated that the rate of actin filament destruction is also dependent upon temperature, buffer type, buffer concentration, and pH, and requires the continued presence of OSO4. The conditions most favorable to filament preservation are fixation in a low concentration of OSO4 for a short time at 0°C in 100mM sodium phosphate buffer, pH 6.0.

On Future Directions in Pathology

1982 ◽  
Vol 40 ◽  
pp. 274-277
Author(s):  
Benjamin F. Trump ◽  
Irene K. Berezesky ◽  
Raymond T. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Pathology ◽  
Future Directions ◽  
Diagnostic Pathology ◽  
The Past ◽  
Transmission Electron ◽  
Organ Systems ◽  
The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

The role of differential phase contrast in electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 176-177
Author(s):  
E.M. Waddell ◽  
J.N. Chapman ◽  
R.P. Ferrier
Keyword(s):  
Phase Contrast ◽  
Practical Method ◽  
Position Vector ◽  
Differential Phase ◽  
Pure Phase ◽  
Differential Phase Contrast ◽  
The Difference ◽  
Image Position ◽  
First Moment

Dekkers and de Lang (1977) have discussed a practical method of realising differential phase contrast in a STEM. The method involves taking the difference signal from two semi-circular detectors placed symmetrically about the optic axis and subtending the same angle (2α) at the specimen as that of the cone of illumination. Such a system, or an obvious generalisation of it, namely a quadrant detector, has the characteristic of responding to the gradient of the phase of the specimen transmittance. In this paper we shall compare the performance of this type of system with that of a first moment detector (Waddell et al.1977).For a first moment detector the response function R(k) is of the form R(k) = ck where c is a constant, k is a position vector in the detector plane and the vector nature of R(k)indicates that two signals are produced. This type of system would produce an image signal given bywhere the specimen transmittance is given by a (r) exp (iϕ (r), r is a position vector in object space, ro the position of the probe, ⊛ represents a convolution integral and it has been assumed that we have a coherent probe, with a complex disturbance of the form b(r-ro) exp (iζ (r-ro)). Thus the image signal for a pure phase object imaged in a STEM using a first moment detector is b2 ⊛ ▽ø. Note that this puts no restrictions on the magnitude of the variation of the phase function, but does assume an infinite detector.

Transmission Electron Microscopy studies of texture of Cr underlayer of magnetic recording hard disk

1991 ◽  
Vol 49 ◽  
pp. 580-581
Author(s):  
L. Tang ◽  
G. Thomas ◽  
M. R. Khan ◽  
S. L. Duan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Magnetic Recording ◽  
Magnetic Thin Films ◽  
Magnetic Films ◽  
Substrate Bias ◽  
Epitaxial Relationship ◽  
Transmission Electron

Cr thin films are often used as underlayers for Co alloy magnetic thin films, such as Co1, CoNi2, and CoNiCr3, for high density longitudinal magnetic recording. It is belived that the role of the Cr underlayer is to control the growth and texture of the Co alloy magnetic thin films, and, then, to increase the in plane coercivity of the films. Although many epitaxial relationship between the Cr underlayer and the magnetic films, such as ﹛1010﹜Co/ {110﹜Cr4, ﹛2110﹜Co/ ﹛001﹜Cr5, ﹛0002﹜Co/﹛110﹜Cr6, have been suggested and appear to be related to the Cr thickness, the texture of the Cr underlayer itself is still not understood very well. In this study, the texture of a 2000 Å thick Cr underlayer on Nip/Al substrate for thin films of (Co75Ni25)1-xTix dc-sputtered with - 200 V substrate bias is investigated by electron microscopy.

Transmission Electron Microscopy of Evaporated Perylene Thin Films

1990 ◽  
Vol 48 (2) ◽  
pp. 336-337
Author(s):  
C. Ewins ◽  
J.R. Fryer
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Molecular Electronics ◽  
High Vacuum ◽  
Amorphous Layer ◽  
Electric Heater ◽  
Transmission Electron ◽  
Polycyclic Aromatic

The preparation of thin films of organic molecules is currently receiving much attention because of the need to produce good quality thin films for molecular electronics. We have produced thin films of the polycyclic aromatic, perylene C10H12 by evaporation under high vacuum onto a potassium chloride (KCl) substrate. The role of substrate temperature in determining the morphology and crystallography of the films was then investigated by transmission electron microscopy (TEM).The substrate studied was the (001) face of a freshly cleaved crystal of KCl. The temperature of the KCl was controlled by an electric heater or a cold finger. The KCl was heated to 200°C under a vacuum of 10-6 torr and allowed to cool to the desired temperature. The perylene was then evaporated over a period of one minute from a molybdenum boat at a distance of 10cm from the KCl. The perylene thin film was then backed with an amorphous layer of carbon and floated onto copper microscope grids.

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