scholarly journals Time-resolved X-ray microscopy of nanoparticle aggregates under oscillatory shear

2009 ◽  
Vol 16 (2) ◽  
pp. 307-309 ◽  
Author(s):  
G. K. Auernhammer ◽  
K. Fauth ◽  
B. Ullrich ◽  
J. Zhao ◽  
M. Weigand ◽  
...  
Keyword(s):  
Piezo Actuator ◽  
Mechanical Stimuli ◽  
Time Resolved ◽  
Shear Cell ◽  
Magnetite Nanoparticle ◽  
X Ray ◽  
Detection Techniques ◽  
Scanning Transmission ◽  
Nanoparticle Aggregates ◽  
Current Detection

Of all the current detection techniques with nanometre resolution, only X-ray microscopy allows imaging of nanoparticles in suspension. Can it also be used to investigate structural dynamics? When studying the response to mechanical stimuli, the challenge lies in its application with a precision comparable with the spatial resolution. In the first shear experiments performed in an X-ray microscope, this has been accomplished by inserting a piezo actuator driven shear cell into the focal plane of a scanning transmission X-ray microscope. Thus shear-induced re-organization of magnetite nanoparticle aggregates could be demonstrated in suspension. As X-ray microscopy proves suitable for studying structural change, new prospects open up in physics at small length scales.

scholarly journals Time-of-arrival detection for time-resolved scanning transmission X-ray microscopy imaging

2020 ◽  
Vol 27 (5) ◽  
pp. 1320-1325
Author(s):  
Simone Finizio ◽  
Sina Mayr ◽  
Jörg Raabe
Keyword(s):  
Light Source ◽  
Temporal Resolution ◽  
Time Of Arrival ◽  
Hybrid Mode ◽  
Microscopy Imaging ◽  
Time Resolved ◽  
X Ray ◽  
Swiss Light Source ◽  
Scanning Transmission ◽  
Synchrotron Light

A setup for time-resolved scanning transmission X-ray microscopy imaging is presented, which allows for an increase in the temporal resolution without the requirement of operating the synchrotron light source with low-α optics through the measurement of the time-of-arrival of the X-ray photons. Measurements of two filling patterns in hybrid mode of the Swiss Light Source are presented as a first proof-of-principle and benchmark for the performances of this new setup. From these measurements, a temporal resolution on the order of 20–30 ps could be determined.

scholarly journals Extracting the Dynamic Magnetic Contrast in Time-Resolved X-ray Transmission Microscopy

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 940 ◽  
Author(s):  
Taddäus Schaffers ◽  
Thomas Feggeler ◽  
Santa Pile ◽  
Ralf Meckenstock ◽  
Martin Buchner ◽  
...  
Keyword(s):  
Magnetic Circular Dichroism ◽  
Opening Angle ◽  
Magnetic Excitations ◽  
Time Resolved ◽  
Transmission Microscopy ◽  
Detection Scheme ◽  
X Ray ◽  
Magnetic Contrast ◽  
Scanning Transmission ◽  
20 Nm

Using a time-resolved detection scheme in scanning transmission X-ray microscopy (STXM), we measured element resolved ferromagnetic resonance (FMR) at microwave frequencies up to 10 GHz and a spatial resolution down to 20 nm at two different synchrotrons. We present different methods to separate the contribution of the background from the dynamic magnetic contrast based on the X-ray magnetic circular dichroism (XMCD) effect. The relative phase between the GHz microwave excitation and the X-ray pulses generated by the synchrotron, as well as the opening angle of the precession at FMR can be quantified. A detailed analysis for homogeneous and inhomogeneous magnetic excitations demonstrates that the dynamic contrast indeed behaves as the usual XMCD effect. The dynamic magnetic contrast in time-resolved STXM has the potential be a powerful tool to study the linear and nonlinear, magnetic excitations in magnetic micro- and nano-structures with unique spatial-temporal resolution in combination with element selectivity.

scholarly journals Why is my image noisy? A look into the terms contributing to a time-resolved X-ray microscopy image

2021 ◽  
Vol 28 (4) ◽  
Author(s):  
Simone Finizio ◽  
Benjamin Watts ◽  
Jörg Raabe
Keyword(s):  
Photon Flux ◽  
Dynamical Process ◽  
Time Resolved ◽  
X Ray ◽  
Microscopy Image ◽  
Experimental Parameters ◽  
Scanning Transmission ◽  
Imaging Conditions ◽  
Microscopy Images

Through Monte Carlo simulations, we investigate how various experimental parameters can influence the quality of time-resolved scanning transmission X-ray microscopy images. In particular, the effect of the X-ray photon flux, of the thickness of the investigated samples, and of the frequency of the dynamical process under investigation on the resulting time-resolved image are investigated. The ideal sample and imaging conditions that allow for an optimal image quality are then identifed.

In Situ Spatial and Time-Resolved Studies of Electrochemical Reactions by Scanning Transmission X-ray Microscopy

2005 ◽  
Vol 77 (11) ◽  
pp. 3479-3487 ◽  
Author(s):  
Daniel Guay ◽  
Jacob Stewart-Ornstein ◽  
Xuerong Zhang ◽  
Adam P. Hitchcock
Keyword(s):  
Electrochemical Reactions ◽  
Time Resolved ◽  
X Ray ◽  
Scanning Transmission

Development of a user-friendly time resolved scanning transmission x-ray microscope at the Advanced Light Source

2021 ◽  
Author(s):  
Hendrik Ohldag ◽  
Thomas Feggeler ◽  
David A. Shapiro ◽  
Yatish Kumar ◽  
Gregory Portman ◽  
...  
Keyword(s):  
Light Source ◽  
Time Resolved ◽  
X Ray ◽  
Advanced Light Source ◽  
Scanning Transmission ◽  
User Friendly

Microtubule nucleation sequence studied by time-resolved x-ray scattering and electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 766-767
Author(s):  
Eva-Maria Mandelkow ◽  
Eckhard Mandelkow ◽  
Joan Bordas
Keyword(s):  
Electron Microscopy ◽  
Dynamic Equilibrium ◽  
Time Resolved ◽  
X Ray ◽  
Additional Information ◽  
X Ray Scattering ◽  
Low Concentrations ◽  
Microtubule Growth ◽  
Ray Patterns ◽  
Ray Scattering

When a solution of microtubule protein is changed from non-polymerising to polymerising conditions (e.g. by temperature jump or mixing with GTP) there is a series of structural transitions preceding microtubule growth. These have been detected by time-resolved X-ray scattering using synchrotron radiation, and they may be classified into pre-nucleation and nucleation events. X-ray patterns are good indicators for the average behavior of the particles in solution, but they are difficult to interpret unless additional information on their structure is available. We therefore studied the assembly process by electron microscopy under conditions approaching those of the X-ray experiment. There are two difficulties in the EM approach: One is that the particles important for assembly are usually small and not very regular and therefore tend to be overlooked. Secondly EM specimens require low concentrations which favor disassembly of the particles one wants to observe since there is a dynamic equilibrium between polymers and subunits.

Microanalysis of precipitates in a ferritic steel

1978 ◽  
Vol 36 (1) ◽  
pp. 618-619
Author(s):  
J.M. Titchmarsh
Keyword(s):  
Ferritic Steel ◽  
Particle Identification ◽  
Energy Dispersive ◽  
Objective Lens ◽  
Ferritic Steels ◽  
Replica Technique ◽  
X Ray ◽  
Large Numbers ◽  
Scanning Transmission ◽  
Made In

The advances in recent years in the microanalytical capabilities of conventional TEM's fitted with probe forming lenses allow much more detailed investigations to be made of the microstructures of complex alloys, such as ferritic steels, than have been possible previously. In particular, the identification of individual precipitate particles with dimensions of a few tens of nanometers in alloys containing high densities of several chemically and crystallographically different precipitate types is feasible. The aim of the investigation described in this paper was to establish a method which allowed individual particle identification to be made in a few seconds so that large numbers of particles could be examined in a few hours.A Philips EM400 microscope, fitted with the scanning transmission (STEM) objective lens pole-pieces and an EDAX energy dispersive X-ray analyser, was used at 120 kV with a thermal W hairpin filament. The precipitates examined were extracted using a standard C replica technique from specimens of a 2¼Cr-lMo ferritic steel in a quenched and tempered condition.

High-resolution x-ray imaging of small copper-rich precipitates in steels

1988 ◽  
Vol 46 ◽  
pp. 528-529
Author(s):  
J. R. Michael ◽  
K. A. Taylor
Keyword(s):  
Electron Microscopy ◽  
Thermomechanical Processing ◽  
Atom Probe ◽  
Ferrite Matrix ◽  
Scanning Transmission Electron Microscope ◽  
Probe Field ◽  
X Ray ◽  
Subsequent Transformation ◽  
Transmission Electron ◽  
Scanning Transmission

Although copper is considered an incidental or trace element in many commercial steels, some grades contain up to 1-2 wt.% Cu for precipitation strengthening. Previous electron microscopy and atom-probe/field-ion microscopy (AP/FIM) studies indicate that the precipitation of copper from ferrite proceeds with the formation of Cu-rich bcc zones and the subsequent transformation of these zones to fcc copper particles. However, the similarity between the atomic scattering amplitudes for iron and copper and the small misfit between between Cu-rich particles and the ferrite matrix preclude the detection of small (<5 nm) Cu-rich particles by conventional transmission electron microscopy; such particles have been imaged directly only by FIM. Here results are presented whereby the Cu Kα x-ray signal was used in a dedicated scanning transmission electron microscope (STEM) to image small Cu-rich particles in a steel. The capability to detect these small particles is expected to be helpful in understanding the behavior of copper in steels during thermomechanical processing and heat treatment.

Energy Dispersive X-Ray Measurements of thin Metal Foils

1976 ◽  
Vol 34 ◽  
pp. 426-427
Author(s):  
J. Bentley ◽  
E. A. Kenik
Keyword(s):  
Materials Science ◽  
Energy Dispersive Spectrometer ◽  
Thin Foil ◽  
Thin Metal ◽  
Energy Dispersive ◽  
Thin Specimen ◽  
X Ray ◽  
Metal Foils ◽  
Small Probe ◽  
Scanning Transmission

Instruments combining a 100 kV transmission electron microscope (TEM) with scanning transmission (STEM), secondary electron (SEM) and x-ray energy dispersive spectrometer (EDS) attachments to give analytical capabilities are becoming increasingly available and useful. Some typical applications in the field of materials science which make use of the small probe size and thin specimen geometry are the chemical analysis of small precipitates contained within a thin foil and the measurement of chemical concentration profiles near microstructural features such as grain boundaries, point defect clusters, dislocations, or precipitates. Quantitative x-ray analysis of bulk samples using EDS on a conventional SEM is reasonably well established, but much less work has been performed on thin metal foils using the higher accelerating voltages available in TEM based instruments.

Techniques for cryoultramicrotomy of propane jet frozen biological samples

1986 ◽  
Vol 44 ◽  
pp. 260-261
Author(s):  
B. Craig ◽  
L. Hawkey ◽  
A. LeFurgey
Keyword(s):  
Freeze Fracture ◽  
Freeze Substitution ◽  
Heart Cells ◽  
Crystal Formation ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Chick Heart ◽  
Embryonic Chick Heart ◽  
A New Technique

Ultra-rapid freezing followed by cryoultramicrotomy is essential for the preservation of diffusible elements in situ within cells prior to scanning transmission electron microscopy and quantitative energy dispersive x-ray microanalysis. For cells or tissue fragments in suspension and for monolayer cell cultures, propane jet freezing provides cooling rates greater than 30,000°C/sec with regions up to 40μm in thickness free of significant ice crystal formation. While this method of freezing has frequently been applied prior to freeze fracture or freeze substitution, it has not been widely utilized prior to cryoultramicrotomy and subsequent x-ray microanalytical studies. This report describes methods devised in our laboratory for cryosectioning of propane jet frozen kidney proximal tubule suspensions and cultured embryonic chick heart cells, in particular a new technique for mounting frozen suspension specimens for sectioning. The techniques utilize the same specimen supports and sample holders as those used for freeze fracture and freeze substitution and should be generally applicable to any cell suspension or culture preparation.

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