scholarly journals Observation of the Triplet Metastable State of Shallow Donor Pairs in AlN Crystals with a Negative-UBehavior: A High-Frequency EPR and ENDOR Study

2008 ◽  
Vol 100 (25) ◽  
Author(s):  
Sergei B. Orlinskii ◽  
Jan Schmidt ◽  
Pavel G. Baranov ◽  
Matthias Bickermann ◽  
Boris M. Epelbaum ◽  
...  
Keyword(s):  
Metastable State ◽  
High Frequency ◽  
Shallow Donor

Investigation of the Dependence of Argon Metastable State Population on the Conditions of High-Frequency Glow Discharge Excitation

2013 ◽  
Vol 56 (1) ◽  
pp. 72-77
Author(s):  
B. T. Baisova ◽  
A. S. Demin ◽  
A. A. Pushkarev ◽  
V. I. Strunin ◽  
G. Zh. Khudaibergenov
Keyword(s):  
Glow Discharge ◽  
Metastable State ◽  
High Frequency ◽  
State Population ◽  
Discharge Excitation

scholarly journals Further Evidence for Carotenoids Engaged in a Metastable State in Photosynthesis

1971 ◽  
Vol 26 (1) ◽  
pp. 51-53 ◽  
Author(s):  
H.-E. Buchwald ◽  
Ch. Wolff
Keyword(s):  
Excitation Energy ◽  
Chlorophyll A ◽  
Metastable State ◽  
High Frequency ◽  
Flash Technique

During photosynthesis a metastable state is formed by superfluous excitation energy. Only carotenoids are responsible for the metastable state. Especially no chlorophyll-a is involved in this state. This result was obtained by using the repetitive ultra-short-flash technique in combination with the high frequency modulated measuring light technique.

Magnetic Bistability of the “Small Disk on Big Disk” Structure

2014 ◽  
Vol 215 ◽  
pp. 499-502
Author(s):  
Maxim E. Stebliy ◽  
Alexey V. Ognev ◽  
Alexander Samardak ◽  
Margarita Anisimova ◽  
Vladimir Ryabov ◽  
...  
Keyword(s):  
Metastable State ◽  
Vortex Core ◽  
High Frequency ◽  
Energy Barrier ◽  
Magnetostatic Interaction ◽  
Small Disk ◽  
Micromagnetic Simulations ◽  
Disk Structure ◽  
High Frequency Excitation ◽  
Frequency Excitation

On the basis of the micromagnetic simulations we reveal that in the small disk on big disk (d+D) nanostructure it is possible the sustained existence of a single-domain and vortex configurations of magnetization. The presence of the metastable state is possible due to the energy barrier, which is caused by magnetostatic interaction between disks. Switching between states can be performed by the external high frequency excitation. Magnetization switching of the small disk on big disk nanostructure is determined by the interaction of the vortex core in big disk with z-component of the magnetization of small disk.

Quenching rate of argon metastable state atoms in high frequency Ar-C4F8 discharges

1990 ◽  
Vol 166 (5-6) ◽  
pp. 480-484 ◽  
Author(s):  
R. Claude ◽  
M. Moisan ◽  
A. Ricard ◽  
M.R. Wertheimer
Keyword(s):  
Metastable State ◽  
High Frequency ◽  
Quenching Rate

scholarly journals CONTROLLING ACTIVATED PROCESSES

2001 ◽  
Vol 01 (01) ◽  
pp. C1-C6
Author(s):  
M. I. DYKMAN ◽  
BRAGE GOLDING
Keyword(s):  
Crystal Growth ◽  
Metastable State ◽  
High Frequency ◽  
Applied Field ◽  
Control Mechanisms ◽  
Separation Techniques ◽  
Selective Control ◽  
Periodic Potentials ◽  
Activated Processes

The rates of activated processes, such as escape from a metastable state and nucleation, are exponentially sensitive to an externally applied field. We describe how this applies to modulation by high-frequency fields and illustrate it with experimental observations. The results may lead to selective control of diffusion in periodic potentials, novel control mechanisms for crystal growth, and new separation techniques.

The Microstructure of Steatite (Protoenstatite)

1985 ◽  
Vol 43 ◽  
pp. 236-237
Author(s):  
W. E. Lee ◽  
A. H. Heuer
Keyword(s):  
High Frequency ◽  
Glass Ceramics ◽  
Magnesium Silicate ◽  
Beam Current ◽  
Glassy Matrix ◽  
Angle Of Incidence ◽  
X Ray ◽  
Mechanical And Electrical Properties ◽  
Argon Ions ◽  
High Temperature Polymorph

IntroductionTraditional steatite ceramics, made by firing (vitrifying) hydrous magnesium silicate, have long been used as insulators for high frequency applications due to their excellent mechanical and electrical properties. Early x-ray and optical analysis of steatites showed that they were composed largely of protoenstatite (MgSiO3) in a glassy matrix. Recent studies of enstatite-containing glass ceramics have revived interest in the polymorphism of enstatite. Three polymorphs exist, two with orthorhombic and one with monoclinic symmetry (ortho, proto and clino enstatite, respectively). Steatite ceramics are of particular interest a they contain the normally unstable high-temperature polymorph, protoenstatite.Experimental3mm diameter discs cut from steatite rods (∼10” long and 0.5” dia.) were ground, polished, dimpled, and ion-thinned to electron transparency using 6KV Argon ions at a beam current of 1 x 10-3 A and a 12° angle of incidence. The discs were coated with carbon prior to TEM examination to minimize charging effects.

Simulations of high-resolution images of amorphous silicon films

1986 ◽  
Vol 44 ◽  
pp. 544-545
Author(s):  
G. Y. Fan ◽  
J. M. Cowley
Keyword(s):  
Electron Microscope ◽  
High Frequency ◽  
Fourier Transformation ◽  
Amorphous Materials ◽  
Low Frequency ◽  
Chromatic Aberration ◽  
Structure Information ◽  
Frequency Components ◽  
High Resolution Images ◽  
Spatial Frequency Spectrum

It is well known that the structure information on the specimen is not always faithfully transferred through the electron microscope. Firstly, the spatial frequency spectrum is modulated by the transfer function (TF) at the focal plane. Secondly, the spectrum suffers high frequency cut-off by the aperture (or effectively damping terms such as chromatic aberration). While these do not have essential effect on imaging crystal periodicity as long as the low order Bragg spots are inside the aperture, although the contrast may be reversed, they may change the appearance of images of amorphous materials completely. Because the spectrum of amorphous materials is continuous, modulation of it emphasizes some components while weakening others. Especially the cut-off of high frequency components, which contribute to amorphous image just as strongly as low frequency components can have a fundamental effect. This can be illustrated through computer simulation. Imaging of a whitenoise object with an electron microscope without TF limitation gives Fig. 1a, which is obtained by Fourier transformation of a constant amplitude combined with random phases generated by computer.

SEM image sharpness analysis

1996 ◽  
Vol 54 ◽  
pp. 142-143
Author(s):  
M. T. Postek ◽  
A. E. Vladar
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Quantitative Information ◽  
Primary Electron ◽  
Image Sharpness ◽  
Critical Dimensions ◽  
Sem Image ◽  
Frequency Changes ◽  
Electron Microscopes ◽  
Scanning Electron

Fully automated or semi-automated scanning electron microscopes (SEM) are now commonly used in semiconductor production and other forms of manufacturing. The industry requires that an automated instrument must be routinely capable of 5 nm resolution (or better) at 1.0 kV accelerating voltage for the measurement of nominal 0.25-0.35 micrometer semiconductor critical dimensions. Testing and proving that the instrument is performing at this level on a day-by-day basis is an industry need and concern which has been the object of a study at NIST and the fundamentals and results are discussed in this paper.In scanning electron microscopy, two of the most important instrument parameters are the size and shape of the primary electron beam and any image taken in a scanning electron microscope is the result of the sample and electron probe interaction. The low frequency changes in the video signal, collected from the sample, contains information about the larger features and the high frequency changes carry information of finer details. The sharper the image, the larger the number of high frequency components making up that image. Fast Fourier Transform (FFT) analysis of an SEM image can be employed to provide qualitiative and ultimately quantitative information regarding the SEM image quality.

Real Ear Sound Pressure Levels Developed by Three Portable Stereo System Earphones

1992 ◽  
Vol 1 (4) ◽  
pp. 52-55 ◽  
Author(s):  
Gail L. MacLean ◽  
Andrew Stuart ◽  
Robert Stenstrom
Keyword(s):  
High Frequency ◽  
Sound Pressure ◽  
Low Frequency ◽  
Test System ◽  
Output Frequency ◽  
Frequency Effects ◽  
Adult Men ◽  
Frequency Responses ◽  
Significant Difference ◽  
Sound Pressure Levels

Differences in real ear sound pressure levels (SPLs) with three portable stereo system (PSS) earphones (supraaural [Sony Model MDR-44], semiaural [Sony Model MDR-A15L], and insert [Sony Model MDR-E225]) were investigated. Twelve adult men served as subjects. Frequency response, high frequency average (HFA) output, peak output, peak output frequency, and overall RMS output for each PSS earphone were obtained with a probe tube microphone system (Fonix 6500 Hearing Aid Test System). Results indicated a significant difference in mean RMS outputs with nonsignificant differences in mean HFA outputs, peak outputs, and peak output frequencies among PSS earphones. Differences in mean overall RMS outputs were attributed to differences in low-frequency effects that were observed among the frequency responses of the three PSS earphones. It is suggested that one cannot assume equivalent real ear SPLs, with equivalent inputs, among different styles of PSS earphones.

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