A computer-control program for TEM in situ fatigue experiments

1989 ◽  
Vol 47 ◽  
pp. 620-621
Author(s):  
Kenneth S. Vecchio ◽  
John A. Hunt
Keyword(s):  
Slow Crack Growth ◽  
Computer Control ◽  
Control Program ◽  
Video Tape ◽  
Computer Control System ◽  
Transmission Electron ◽  
In Situ Experiments ◽  
Tremendous Amount ◽  
And Control

In-situ experiments conducted within a transmission electron microscope provide the operator a unique opportunity to directly observe microstructural phenomena, such as phase transformations and dislocation-precipitate interactions, “as they happen”. However, in-situ experiments usually require a tremendous amount of experimental preparation beforehand, as well as, during the actual experiment. In most cases the researcher must operate and control several pieces of equipment simultaneously. For example, in in-situ deformation experiments, the researcher may have to not only operate the TEM, but also control the straining holder and possibly some recording system such as a video tape machine. When it comes to in-situ fatigue deformation, the experiments became even more complicated with having to control numerous loading cycles while following the slow crack growth. In this paper we will describe a new method for conducting in-situ fatigue experiments using a camputer-controlled tensile straining holder.The tensile straining holder used with computer-control system was manufactured by Philips for the Philips 300 series microscopes. It was necessary to modify the specimen stage area of this holder to work in the Philips 400 series microscopes because the distance between the optic axis and holder airlock is different than in the Philips 300 series microscopes. However, the program and interfacing can easily be modified to work with any goniometer type straining holder which uses a penrmanent magnet motor.

Design and Research on Variable-Rate Fertilization Computer Control System

2012 ◽  
Vol 249-250 ◽  
pp. 610-615
Author(s):  
Shu Fa Chen ◽  
Cheng Long Feng ◽  
Shi Ping Zhang
Keyword(s):  
Control System ◽  
Paddy Field ◽  
Computer Control ◽  
Control Element ◽  
System Control ◽  
Variable Rate ◽  
Computer Control System ◽  
Working Mechanism ◽  
Working Performance ◽  
And Control

Based on domestic and foreign research situations of variable-rate fertilizing technology, the overall structure and working mechanism of variable-rate fertilizing machine were described, control content and strategy of control system were studied, AT89C5 SCM was used as a core control element in control system, control system hardware and software were designed and integrated. Variable-rate fertilizing experiments in space and paddy field showed that working efficiency of the spreader was up to 6 hm2/h, fertilizing error was less than 5%, fertilizing stability variation coefficient was less than 6.2%, working performance and control system design of the fertilizer can satisfy the demand of variable-rate fertilization in paddy field.

scholarly journals Imaging, understanding, and control of nanoscale materials transformations

MRS Bulletin ◽  
2021 ◽  
Author(s):  
Haimei Zheng
Keyword(s):  
Solid Electrolyte Interphase ◽  
Time Resolved ◽  
Nanocrystal Growth ◽  
Transmission Electron ◽  
Lithium Dendrites ◽  
Liquid Cell ◽  
Resolution Imaging ◽  
And Control

AbstractThe development of liquid cells for transmission electron microscopy has enabled breakthroughs in our ability to follow nanoscale structural, morphological, or chemical changes during materials growth and applications. Time-resolved high-resolution imaging and chemical analysis through liquids opened the opportunity to capture nanoscale dynamic processes of materials, including reaction intermediates and the transformation pathways. In this article, a series of work is highlighted with topics ranging from liquid cell developments to in situ studies of nanocrystal growth and transformations, dendrite formation, and suppression of lithium dendrites through in situ characterization of the solid–electrolyte interphase chemistry. The understanding garnered is expected to accelerate the discovery of novel materials for applications in energy storage, catalysis, sensors, and other functional devices.

In-Situ Annealing of Metal Thin Films on Silicon

1981 ◽  
Vol 39 ◽  
pp. 164-165
Author(s):  
L. J. Chen ◽  
J. W. Mayer
Keyword(s):  
Thin Films ◽  
Device Fabrication ◽  
Electron Gun ◽  
Specimen Thickness ◽  
Metal Thin Films ◽  
Thin Foils ◽  
Transmission Electron ◽  
In Situ Experiments ◽  
Annealing Study

In-situ dynamical experiments in the transmission electron microscope (TEM) have long interested electron microscopists. In designing and performing the experiments, it is important to minimize the influences of the factors, which include the specimen thickness, electron beam heating, electron irradiation and specimen environments that may affect the validity of in-situ experiments. Comparisons of the results with those of other experiments are also very desirable.In microelectronic device fabrication process, it has become increasingly common to react a few hundred Å in thickness metal films with silicon substrate to form silicide contacts. Ni thin films on silicon have been chosen for in-situ annealing study since this system has been extensively investigated by Rutherford backscattering and glancing angle x-ray experiments. In-situ annealing of Co, Mo, Ti, Pd and W thin films on silicon have also been performed.Ni films, 300 and 400 Å thick, were electron gun deposited on (001) n-type silicon. Thin foils for TEM examination were chemically polished from silicon side. A JEOL 100B microscope equipped with a side entry, single tilt hot stage was used for TEM study.

In situ tEM observation of C49 to C54 TiSi2 transformation

1992 ◽  
Vol 50 (2) ◽  
pp. 1356-1357
Author(s):  
K. Barmak ◽  
L.E. Levine ◽  
D.A. Smith ◽  
Y. Komemt
Keyword(s):  
High Resistivity ◽  
In Situ Tem ◽  
Video Tape ◽  
Furnace Annealing ◽  
Plan View ◽  
Transmission Electron ◽  
In Situ Heating ◽  
Face Centered ◽  
Si Wafer

The reaction of thin films of Ti with Si results in the formation of the high resistivity (≃150 μΩcm) base-centered orthorhombic C49 phase prior to the low resistivity (≃15-20 μΩcm) face-centered orthorhombic C54 phase. In our experiments, 30 nm of Ti was evaporated onto a < 100 > oriented Si wafer cleaned in a 10:1 H2O:HF solution. The wafer had been previously implanted with As to a dose of 5×l015 cm−2. Mixed C49/C54 phase films were obtained by furnace annealing at 700°C for 10 min. Plan view transmission electron microscopy (TEM) specimens were prepared by dimpling and etching in a 10:6:6 HNO3:HF:CH3COOH solution. The sample was initially studied in a JEOL 4000FX and in situ heating experiments were carried out in a Philips 430 operating at 300 kV. The progress of the transformation was recorded on video tape. The temperature was raised relatively quickly to 700°C and then more slowly to 750°C.

Possibility of an integrated transmission electron microscope: enabling complex in-situ experiments

2021 ◽  
Vol 56 (9) ◽  
pp. 5309-5320
Author(s):  
Khalid Hattar ◽  
Katherine L. Jungjohann
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Extreme Environments ◽  
Structure Property ◽  
Multispectral Data ◽  
Transmission Electron ◽  
Holistic Understanding ◽  
In Situ Experiments ◽  
Scanning Transmission

Abstract Multimodal in-situ experiments are the wave of the future, as this approach will permit multispectral data collection and analysis during real-time nanoscale observation. In contrast, the evolution of technique development in the electron microscopy field has generally trended toward specialization and subsequent bifurcation into more and more niche instruments, creating a challenge for reintegration and backward compatibility for in-situ experiments on state-of-the-art microscopes. We do not believe this to be a requirement in the field; therefore, we propose an adaptive instrument that is designed to allow nearly simultaneous collection of data from aberration-corrected transmission electron microscopy (TEM), probe-corrected scanning transmission electron microscopy, ultrafast TEM, and dynamic TEM with a flexible in-situ testing chamber, where the entire instrument can be modified as future technologies are developed. The value would be to obtain a holistic understanding of the underlying physics and chemistry of the process-structure–property relationships in materials exposed to controlled extreme environments. Such a tool would permit the ability to explore, in-situ, the active reaction mechanisms in a controlled manner emulating those of real-world applications with nanometer and nanosecond resolution. If such a powerful tool is developed, it has the potential to revolutionize our materials understanding of nanoscale mechanisms and transients. Graphical Abstract

scholarly journals In situ experiments on the effect of low pH on the ultrastructure of the seagrasses Cymodocea nodosa and Posidonia oceanica

2021 ◽  
Author(s):  
MARIA KOUTALIANOU ◽  
MARIA CRISTINA BUIA ◽  
CHRISTOS KATSAROS
Keyword(s):  
Cell Structure ◽  
Posidonia Oceanica ◽  
Control Area ◽  
Low Ph ◽  
Cymodocea Nodosa ◽  
Transmission Electron ◽  
In Situ Experiments ◽  
Young Leaves ◽  
Tubulin Immunofluorescence

The present study investigates the impacts of low pH on the cell structure of the seagrasses Posidonia oceanica (L.) Delile and Cymodocea nodosa (Ucria) Ascherson. The study was applied with in situ experiments at the Castello Aragonese of Ischia (Naples, Italy), where shallow submarine vents, lowering the pH, can be used as natural laboratories. Shoots of the seagrasses were transferred from the control area (pH 8.1) to the two venting areas (pH 7.8 and 6.8) for different times. Epidermal cells of young leaves were examined using transmission electron microscopy (TEM) and tubulin immunofluorescence. After one week at pH 7.8, the cell structure of Posidonia oceanica was normal, while in Cymodocea nodosa microtubule (MT) network and cell structure were affected. In addition, in C. nodosa, ultrastructural analysis revealed a gradual degradation of the nuclei, a disorganization of the chloroplasts, and an increase in the number of mitochondria and dictyosomes. The exposure of both plants for 3 weeks at pH 6.8 resulted in the aggregation and finally in the dilation of the endoplasmic reticulum (ER) membranes. Tubulin immunofluorescence revealed that after three weeks, the MT cytoskeleton of both plants was severely affected. All these alterations can be considered as indications of an apoptotic like programmed cell death (AL-PCD) which may be executed in order to regulate stress response.

scholarly journals In situ straining experiments in the Transmission Electron Microscope

1990 ◽  
Vol 48 (4) ◽  
pp. 518-519
Author(s):  
Ulrich Messerschmidt
Keyword(s):  
Effective Stress ◽  
Line Tension ◽  
Prismatic Slip ◽  
Water Cooling ◽  
Transmission Electron ◽  
In Situ Experiments ◽  
Ordered Alloys ◽  
Kinematic Behaviour

Recently a number of in situ straining experiments have been carried out at temperatures between about 80 K and 1200 K. A new HVEM straining stage was constructed for temperatures above 1300 K. Its design features are: top entry double tilting stage, thermal expansion drive of high stiffness, heating by electron bombardment, and water cooling to quickly reach a steady state.The following deformation phenomena have successfully been treated by in situ experiments:Determination of the effective stress from the curvature of bowed-out dislocation segments: As shown by in situ experiments on MgO crystals, the line tension of dislocations may differ from its theoretical value. Nevertheless, the anomalous temperature dependence of the effective stress in ordered alloys as well as for prismatic slip in Be has been determined in accordance with macroscopic experiments. Measurement of velocities and kinematic behaviour of dislocations: In situ experiments allow the coordination of the motion of individual dislocation segments with their geometrical configuration.

In situ Transmission Electron Microscope observations of mesotaxial silicide formation in the CoSi2/Si system

1989 ◽  
Vol 47 ◽  
pp. 452-453
Author(s):  
R. Hull ◽  
A.E. White ◽  
K.T. Short ◽  
S.M. Yalisove ◽  
D. Loretto
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Ex Situ ◽  
Metal Silicide ◽  
Silicide Formation ◽  
Plan View ◽  
Silicide Layer ◽  
Transmission Electron ◽  
In Situ Experiments

A new technique for synthesis of buried epitaxial metal silicide layers in Si (“mesotaxy”) by high-dose implantation of Co and Ni into Si surfaces has been developed. Subsequent to implantation at energies in the few hundred keV range and doses in the 1017Cm−2 regime, thermal annealing at temperatures up to 1000°C results in the formation of well-defined and relatively high quality Si/metal disilicide/Si structures.The exact implantation and processing conditions are crucial in determining the structure and quality of the buried silicide layer. In this work, we describe transmission electron microscope experiments which illuminate the silicide formation process both by static studies of as-implanted and annealed structures, and dynamical in-situ experiments where as-implanted structures are annealed inside the microscope to mimic the ex-situ annealing conditions. The structure geometry in these materials turns out to be close to ideal for such in-situ experimentation: typical implantation conditions for formation of a contiguous silicide layer result in tlqe metal layers being of the order a few hundred to a thousand Å and buried about 600-1000 Å below the Si surface. In-situ annealing in the plan-view geometry inhibits surface diffusion across the interfaces, which would be expected in the cross-sectional geometry (5). The typical penetration depths attainable in Si with 200 keV electrons, say ~ 1 micron, allow a significant thickness, hsubthin of Si substrate below the metal layer, thickness hm, to be retained during the in-situ experiment such that hm ≪hsubthin. This is important, as it ensures that the film stress condition (which arises because of the difference in bulk lattice parameters between the Si and metal silicide layers) is reasonably representative of the stress conditions relevant for the case of annealing on the unthinned substrate.

In situ TEM studies of deformation and fracture

1989 ◽  
Vol 47 ◽  
pp. 622-623
Author(s):  
I.M. Robertson ◽  
T.C. Lee ◽  
D.K. Dewald ◽  
H.K. Birnbaum
Keyword(s):  
Grain Boundary ◽  
Video Camera ◽  
In Situ Tem ◽  
Video Tape ◽  
Slip Systems ◽  
Camera System ◽  
Dynamic Events ◽  
Transmission Electron ◽  
Deformation And Fracture

The in-situ TEM straining technique has been used to investigate the micromechanisms of deformation and fracture in several ductile and semi-brittle systems. Attention has been focussed on the dislocation structures ahead of advancing cracks and on the interaction between lattice dislocations and grain boundaries.The deformation experiments were performed in-situ in a transmission electron microscope equipped with a video camera system. The dynamic events were recorded on video tape with a time resolution of l/30th of a second. Static interactions were recorded using the regular microscope plate system. The straining stage deforms the samples in Mode I and can operate at a displacement rate of 4 in sec-1.An example of one of the possible interactions between lattice dislocations and a ∑- 3 ([ll)/60°) grain boundary in 310 stainless steel is shown in the micrograph in Figure 1. The dislocations on slip systems A (a/2[110)1 (ll) 1 ) and B (a/2[101] (11) 1 ) impinge on the grain boundary, generating slip systems C (a/2[l0) 2/(111) 2) and D (a/2[l0) 2/(111) 2). To understand this effect three conditions were considered:

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