In-Situ Techniques for Studying Epitaxially Grown Layers and Determining their Magnetic Properties

1989 ◽  
Vol 151 ◽  
Author(s):  
B. Heinrich ◽  
A. S. Arrott ◽  
J. F. Cochran ◽  
K. B. Urquhart ◽  
K. Myrtle ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Surface Science ◽  
Easy Axis ◽  
Film Surface ◽  
In Situ Techniques ◽  
Wide Range ◽  
Bcc Structure ◽  
Crystallographic Defects

ABSTRACTUltrathin films of bcc Fe (001) on Ag (001) and Fe/Ni (001) bilayers on Ag were grown by molecular beam epitaxy. A wide range of surface science tools (RHEED, REELFS, AES, and XPS) were employed to establish the quality of epitaxial growth. Ferromagnetic resonance and Brillouin light scattering were used to extract the magnetic properties. Emphasis was placed on the study of magnetic anisotropies. Large uniaxial anisotropies with the easy axis perpendicular to the film surface were observed in all ultrathin structures studied. In sufficiently thin samples the saturation magnetization was oriented perpendicular to the film surface in the absence of an applied field. It has been demonstrated that in bcc Fe films the uniaxial perpendicular anisotropy originates at the film interfaces. Fe/Ni bilayers were also investigated. Ni grows in the pure bcc structure for the first 3–6ML and then transforms to a new structure which exhibits unique magnetic properties. Transformed ultrathin bilayers possesses large in-plane 4th order anisotropies far surpassing those observed in bulk Fe and Ni. The large 4th order anisotropies originate in crystallographic defects formed during the Ni lattice transformation.

Using a Moderate Vacuum, Hot/Cryo-Stage Equipped AFM for In-Situ Observation of α-Phase Growth In 60SN40PB Hypoeutectic Solder

1998 ◽  
Vol 4 (S2) ◽  
pp. 316-317
Author(s):  
D. N. Leonard ◽  
P.E. Russell
Keyword(s):  
Surface Science ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Scanning Tunneling ◽  
In Situ Observation ◽  
Atmospheric Conditions ◽  
Tunneling Microscopy ◽  
Wide Range ◽  
Gas Environment

Atomic force microscopy (AFM) was introduced in 1984, and proved to be more versatile than scanning tunneling microscopy (STM) due to the AFM's capabilities to scan non-conductive samples under atmospheric conditions and achieve atomic resolution. Ultra high vacuum (UHV) AFM has been used in surface science applications when control of oxidation and corrosion of a sample's surface are required. Expensive equipment and time consuming sample exchanges are two drawbacks of the UHV AFM system that limit its use. Until recently, no hot/cryo-stage, moderate vacuum, controlled gas environment AFM was commonly available.We have demonstrated that phase transformations are easily observable in metal alloys and polymers with the use of a moderate vacuum AFM that has in-situ heating/cooling capabilities and quick (within minutes) sample exchange times. This talk will describe the results of experiments involving a wide range of samples designed to make use of the full capabilities of a hot/cryo-stage, controlled gas environment AFM.

scholarly journals In Situ and In Operando Techniques to Study Li-Ion and Solid-State Batteries: Micro to Atomic Level

Inorganics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 85
Author(s):  
Maryam Golozar ◽  
Raynald Gauvin ◽  
Karim Zaghib
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Atomic Level ◽  
X Ray ◽  
In Situ Techniques ◽  
Transmission Electron ◽  
Wide Range ◽  
Li Ion

This work summarizes the most commonly used in situ techniques for the study of Li-ion batteries from the micro to the atomic level. In situ analysis has attracted a great deal of interest owing to its ability to provide a wide range of information about the cycling behavior of batteries from the beginning until the end of cycling. The in situ techniques that are covered are: X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Scanning Transmission Electron Microscopy (STEM). An optimized setup is required to be able to use any of these in situ techniques in battery applications. Depending on the type of data required, the available setup, and the type of battery, more than one of these techniques might be needed. This study organizes these techniques from the micro to the atomic level, and shows the types of data that can be obtained using these techniques, their advantages and their challenges, and possible strategies for overcoming these challenges.

Safe Quality of Service Aware Management of Heterogeneous Sensor Networks

2006 ◽  
Vol 07 (01) ◽  
pp. 179-193 ◽  
Author(s):  
Mohamed Younis ◽  
Waleed Youssef ◽  
Mohamed Eltoweissy ◽  
Stephan Olariu
Keyword(s):  
Quality Of Service ◽  
Network Performance ◽  
Vital Role ◽  
Heterogeneous Sensor Networks ◽  
Evolutionary Neural Network ◽  
Wide Range ◽  
Pervasive Service ◽  
Potential Damage

Wireless networked sensors are envisioned to play a vital role in the emerging pervasive service platforms that will instrument a wide range of next generation civil and military applications. Recently, we have proposed ANSWER: AutoNomouS Wireless sEnsor netwoRk as a service platform whose mission is to provide dependable information services to in-situ mobile users while satisfying their quality-of-service (QoS) requirements. Alongside with the stationary tiny sensors, the network employs more powerful mobile devices referred to as aggregation and forwarding nodes (AFNs). ANSWER exploits AFN mobility to support QoS requirements. However, as an AFN moves closer to an event (for example, a hazardous spill), it may be at risk (for example, due to potential damage). In this paper, we present a quantitative analysis of the interplay and balance between QoS support and asset safety. We propose a new scheme, called SAFER (for SAFEty-aware Relocation), which pursues relocation of the AFN in order to boost network performance without unnecessarily compromising AFN safety. For the relocation process to take place, SAFER uses historical data on detected events and employs an evolutionary neural network to assess the risk involved and predict good quality new position(s). Experimental results demonstrate the effectiveness of SAFER.

scholarly journals The analysis on the correlation parameters of the embankment compaction under in situ conditions

2013 ◽  
Vol 12 (3) ◽  
pp. 097-104
Author(s):  
Maciej Kumor ◽  
Łukasz Kumor ◽  
Joanna Farmas
Keyword(s):  
Particle Size ◽  
In Situ Tests ◽  
Geotechnical Assessment ◽  
In Situ Conditions ◽  
Wide Range ◽  
Correlation Parameters ◽  
And Control

Geotechnical assessment of the implementation correctness of a road embankment wide range of issues, among which important selection and control of the quality of the earthworks are extremely significant. The article presents results of in situ tests determining correlations between the depending parameters defined by a static plate – VSS test – E1 and E2, and obtained from the study LFG Dynamic Load Plate. Studies indicate that the determination of the correlation between the parameters characterizing the particle size distribution (Cc, Cu, D10, D20, D30, D60), and the compaction parameters obtained by examining the compaction of sand embankment (Evd, E1, E2, I0) is physically complex and hence extremely difficult. 

Are major instrumental developments in TEM still to be Expected?

1988 ◽  
Vol 46 ◽  
pp. 646-647
Author(s):  
K.D. van der Mast ◽  
A.J. Koster
Keyword(s):  
Surface Science ◽  
New Technologies ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Analytical Instrument ◽  
Electron Efficiency ◽  
In Situ Experiments ◽  
New Ideas

In general instrumental developments are caused either by new application demands or by the availability of new technologies. If we investigate the trends in application demands, some predictions can be made safely: More and more the TEM will be used as an analytical instrument. The number of desired signals (detectors) will increase and the quality of the signals must be improved in terms of noise and electron efficiency. Examples are parallel collection EELS and Auger detectors (Kruit and Venables, 1988).The first experiments on coincidence techniques are also promising (Kruit et al, 1984) and exciting new ideas are investigated today. Besides this, another area of applications will probably become more important: surface science in situ experiments. Especially for this type of experiments it is difficult to transfer the specimen to another system without spoiling the experiment. So these applications will lead to an ultra high vacuum specimen environment - constructed in a way that many accessories necessary for surface experiments can be added: Ion guns, preparation chamber, knudsen cells etc.

U-Pb zircon (ID-TIMS and SHRIMP) evidence for the early ordovician intrusion of metagranites in the late Proterozoic Canaveilles Group of the Pyrenees and the Montagne Noire (France)

2005 ◽  
Vol 176 (3) ◽  
pp. 269-282 ◽  
Author(s):  
Alain Cocherie ◽  
Thierry Baudin ◽  
Albert Autran ◽  
Catherine Guerrot ◽  
C. Mark Fanning ◽  
...  
Keyword(s):  
Late Proterozoic ◽  
The North ◽  
Continental Plate ◽  
Wide Range ◽  
Gondwana Margin ◽  
Group A ◽  
Montagne Noire ◽  
Representative Samples

Abstract Depending on the quality of the zircon grains available for analysis, two methods may be used to date igneous rock emplacement, namely U-Pb TIMS with isotope dilution or in situ U-Pb SIMS (SHRIMP). Both methods have been used to determine, in a precise and accurate manner, the emplacement age of the granitic protolith of the various orthogneisses in the Pyrenean Axial Zone. More specifically, four representative samples of G1, G2 and a “transition gneiss” yielded reliable datings with an average age of 473 ± 4 Ma for each sample. The surrounding sediments of the Canaveilles Group were constrained by zircon grains from interlayered metarhyodacite and dated at 581 ± 10 Ma using the SHRIMP method, clearly giving this group a late Proterozoic (Vendian) age. Finally, the Somail orthogneiss of the Montagne Noire, equivalent to that of the Canigou, yielded an age of 471 ± 4 Ma with the in situ U-Pb method, which is identical to the dating of the Pyrenean samples. In addition, most of the studied orthogneisses recorded a wide range of significant concordant inherited ages spanning from early Archaean (3.5 Ga) to Pan-African/Cadomian (600–800 Ma). Bearing in mind the calc-alkaline affinity of the studied rocks, this work demonstrates the huge contrast between the active Gondwana margin in the north (“South European terrane”) and the remarkably homogeneous continental plate that existed from Arabia to Morocco during the Ordovician.

In-Line In-Situ Direct Measurement of Absolute Biaxial Stress in Pipelines

2006 ◽  
Author(s):  
David A. Russell ◽  
David J. Buttle ◽  
John C. McCarthy
Keyword(s):  
Magnetic Properties ◽  
Recent Work ◽  
Pipe Wall ◽  
Rehabilitation Program ◽  
Biaxial Stress ◽  
Magnetic Response ◽  
Barkhausen Effect ◽  
Detection Techniques ◽  
Wide Range

This paper reports on recent work on the in-situ determination of absolute levels of biaxial stress in ferromagnetic pipeline materials. The response of pipe-wall materials to an applied alternating magnetic field is measured, and knowledge of the variation of magnetic properties of the material used to determine stress values. A wide variety of means are in use to detect, characterize and measure an equally wide range of defects in pipelines. These may arise from pre-existing conditions, errors in construction, effects of corrosion, accidental damage or other causes. Caliper tools, mapping tools, MFL, EMAT and ultrasonic tools are all used to detect conditions that may result in unacceptable stress in a pipeline. The ultimate aim, for all of these detection techniques, is to prove that the inspected pipeline’s fitness for purpose is maintained; and where this is not demonstrated, to provide accurate and reliable information on which to base a rehabilitation program. Recently attention has been raised by a number of groups working on the development of techniques intended to utilize the dependence of the magnetic response of ferrous materials to applied stress in order to directly measure stress. Most of these techniques have been based on the Barkhausen effect. This paper discusses the use of an alternative technique based on other magnetic properties that have been shown to allow derivation of a quantifiable relation between the level of stress present in material and the magnetic response. This technique, named MAPS by its developers, ESR Technology, has been employed with considerable success out-with the pipeline industry. Recent work has concentrated on applications in dynamic situations, in particular in pig-mounted inspection systems. A series of tests are described with dynamic measurements made inside pipes, covering measurement of applied (bending) stresses and artificially simulated defects. Measurements are described at velocities up to 4 m/s in prototype systems at 24” diameter with stand-offs of 2mm and up. Magneto-dynamic effects from the motion of the sensors past the metal of the pipe-wall have been characterized and variations in signal due to the velocity and instrument stand-off are described. It is considered that this work forms the basis for a pipeline inspection technique using these instruments.

The Effect of Thickness on the Magnetic Anisotropy and Magnetic Properties of Single-Layered FePt Films by In Situ Annealing

2010 ◽  
Vol 123-125 ◽  
pp. 507-510
Author(s):  
S.C. Chen ◽  
T.H. Sun ◽  
C.L. Chang ◽  
Chih Long Shen ◽  
G.P. Lin ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Perpendicular Magnetic Anisotropy ◽  
Recording Media ◽  
Magnetic Recording Media ◽  
Fept Film ◽  
Perpendicular Magnetic Recording ◽  
High Density Recording

The FePt films with various thicknesses of 5 to 50 nm are deposited on Si(100) substrate without any underlayer by in-situ annealing at substrate temperature (Ts) of 620°C. A strong (001) texture of L10 FePt film is obtained and presents high perpendicular magnetic anisotropy as the film thickness increases to 30 nm. Further increasing the thickness to above 30 nm, the (111) orientation of L10 FePt is enhanced greatly, indicating that the quality of perpendicular magnetic anisotropy degrades when the FePt film is thicker than 30 nm. The single-layered FePt film with thickness of 30 nm by in-situ depositing at 620°C shows good perpendicular magnetic properties (perpendicular coercivity of 14.0 kOe, saturation magnetization of 473 emu/cm3 and perpendicular squareness of 0.96, respectively), which reveal its significant potential as perpendicular magnetic recording media for high-density recording.

Overview of the 2019 Sentinel-5p TROpomi vaLIdation eXperiment (TROLIX)

2020 ◽  
Author(s):  
Arnoud Apituley ◽  
Karin Kreher ◽  
Ankie Piters ◽  
John Sullivan ◽  
Michel vanRoozendael ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Stratospheric Ozone ◽  
Aerosol Layer ◽  
Data Set ◽  
Local Networks ◽  
Validation Experiment ◽  
Wide Range ◽  
Data Products

<p>For the validation of Sentinel-5p/TROPOMI the TROpomi vaLIdation eXperiment (TROLIX) was held in the Netherlands based at the Cabauw Experimental Site for Atmospheric Research during September 2019. TROLIX consisted of active and passive remote sensing platforms in conjunction with several balloon-borne and surface measurements.</p><p>The intensive observations will serve to establish the quality of TROPOMI L2 main data products (UVAI, Aerosol Layer Height, NO<sub>2</sub>, O<sub>3</sub>, HCHO, Clouds) under realistic conditions with varying cloud cover and a wide range of atmospheric conditions.</p><p>Since TROPOMI is a hyperspectral imager with a very high spatial resolution of 3.6 x 5.6 km<sup>2</sup>, understanding local effects such as inhomogeneous sources of pollution, sub-pixel clouds and variations in ground albedo is important to interpret TROPOMI results. Therefore, the campaign included sub-pixel resolution local networks of sensors, involving MAXDOAS and Pandora instruments, around Cabauw (rural) and within the city of Rotterdam (urban). Utilising its comprehensive in-situ and remote sensing observation program in and around the 213 m meteorological tower, Cabauw was the main site of the campaign with focus on vertical profiling using lidar instruments for aerosols, clouds, water vapor, tropospheric and stratospheric ozone, as well as balloon-borne sensors for NO<sub>2</sub> and ozone.</p><p>The data set collected can be directly compared to the TROPOMI L2 data products, while measurements of parameters related to a-priori data and auxiliary parameters that infuence the quality of the L2 products such as aerosol and cloud profiles and in-situ aerosol and atmospheric chemistry were also collected.</p><p>This paper gives an overview of the campaign, and an overview of the participating main and ancillary instrumentation and preliminary results.</p><p>Future activities include the deployment in 2020 of an airborne hyperspectral imager.</p>

Cathodoluminescence of Catalyst Crystallites

1982 ◽  
Vol 40 ◽  
pp. 664-665
Author(s):  
E.D. Boyes ◽  
P.L. Gai ◽  
D.B. Darby ◽  
C. Warwick
Keyword(s):  
Defect Density ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Semiconductor Materials ◽  
Environmental Cell ◽  
High Resolution Structure ◽  
Commercially Important ◽  
Crystallographic Defects ◽  
Resolution Structure

The extended crystallographic defects introduced into some oxide catalysts under operating conditions may be a consequence and accommodation of the changes produced by the catalytic activity, rather than always being the origin of the reactivity. Operation without such defects has been established for the commercially important tellurium molybdate system. in addition it is clear that the point defect density and the electronic structure can both have a significant influence on the chemical properties and hence on the effectiveness (activity and selectivity) of the material as a catalyst. SEM/probe techniques more commonly applied to semiconductor materials, have been investigated to supplement the information obtained from in-situ environmental cell HVEM, ultra-high resolution structure imaging and more conventional AEM and EPMA chemical microanalysis.

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