Elektrotransportversuche mit epitaktischen Goldschichten

1979 ◽  
Vol 34 (10) ◽  
pp. 1196-1202
Author(s):  
W. Kleinn ◽  
H. Hübner
Keyword(s):  
Activation Energy ◽  
Growth Rate ◽  
Electron Microscope ◽  
Temperature Gradient ◽  
Transmission Electron Microscope ◽  
Direct Current ◽  
Gold Films ◽  
Temperature Range ◽  
Transmission Electron ◽  
Current Densities

Abstract Electrotransport Experiments with Epitaxial Gold Films Electrotransport in gold films of 60 nm thickness grown epitaxially onto hot (100) NaCl substrate is determined from the growth rate of voids forming in the temperature gradient in short specimens observed in the transmission electron microscope while loaded with direct current densities of several 106 A/cm2 . For the temperature range 631 -1214 K an activation energy (1,19 ± 0,05) eV is found.

A Hvem Study of the Electron Irradiated Defects in Nitrogen Doped FZ-Si Single Crystal

1989 ◽  
Vol 163 ◽  
Author(s):  
Gao Yuzun ◽  
T. Takeyama
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Electron Irradiation ◽  
Defect Density ◽  
Migration Energy ◽  
Nitrogen Doped ◽  
Temperature Range ◽  
Transmission Electron ◽  
Excellent Property ◽  
P Type

AbstractHigh voltage transmission electron microscope (JEM-1000) has been used to investigate the electron irradiated defects in in p-type FZ-Si and nitrogen doped p-type FZ-Si. It was found that when the irradiated conditions were the saie ,the irradiated defects were easier to be produced in the FZ-Si than in nitrogen doped FZ-Si in the temperature range 573-773 K. The defect density was higher in the foraer. The migration energy of the vacancies in the temperature range 573-773 K was 0.34 and 0.58 eV for FZ-Si and nitrogen doped FZ-Si respectively. It seems to indicate that there was some interaction between vacancies and nitrogen atoms in the nitrogen doped FZ-Si. The results proved that the nitrogen doped FZ-Si has excellent property against electron irradiation.

Mechanisms of high temperature frictional sliding in Westerly granite

1978 ◽  
Vol 15 (3) ◽  
pp. 361-375 ◽  
Author(s):  
R. M. Stesky
Keyword(s):  
Activation Energy ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Frictional Sliding ◽  
Slip Surfaces ◽  
Transmission Electron ◽  
Experimental Activation Energy ◽  
Small Grains ◽  
Highly Strained ◽  
Quartz Grains

The mechanisms of frictional sliding in faulted Westerly granite were studied in two ways. Firstly, the experimental activation energy was measured from 300 to 700 °C at 2.5 kbar (2.5 × 105 kPa) pressure and sliding rates from 10−5 to 10−2 cm/s. Secondly, fault samples were examined with an optical and a transmission electron microscope. Below 500 °C the activation energy was about 30 kcal/mol (1.3 × 105 J/mol). The fault gouge was porous and consisted of angular randomly oriented grains. The quartz and the feldspars were unstrained, similar to the grains in a room-temperature fault. Above 500 °C the activation energy increased to about 85 kcal/mol (3.6 × 105 J/mol). Plasticity in quartz about 500 °C was observed optically by the presence of highly strained gouge grains and with the transmission electron microscope by a marked increase in dislocation density from 3 × 108 cm−2 initially to greater than 1011 cm−2 at 700 °C. The quartz grains away from the fault were strain-hardened with inhomogeneously distributed, dense tangles of dislocations. In contrast, the small grains (<10 μm) in the gouge contained a low density of dislocations. The feldspars showed no sign of plasticity up to 700 °C. Biotite and muscovite were plastic at all temperatures, forming thin ribbons along slip surfaces in the fault zone. Glass was not identified in any of the faulted samples studied.

In Situ Straining Experiments On Fe70AL30 Single Crystals

1994 ◽  
Vol 364 ◽  
Author(s):  
G. Molenat ◽  
H. Rösner ◽  
E. Nembach
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Single Crystals ◽  
Yield Stress ◽  
Transmission Electron Microscope ◽  
Intermetallic Alloys ◽  
Temperature Range ◽  
Transmission Electron

AbstractWith an aim to contributing to the understanding of the mechanical properties of Fe3Al-based intermetallic alloys, Fe-30 at. % Al single crystals have been strained in a transmission electron microscope below and in the temperature range of the yield stress anomaly (at 300K and 573K respectively).

A Reproducible Selective Stain for Cardiac Sarcoplasmic Reticulum

1974 ◽  
Vol 32 ◽  
pp. 214-215
Author(s):  
R. A. Waugh ◽  
J. R. Sommer
Keyword(s):  
Complex System ◽  
Electron Microscope ◽  
Sarcoplasmic Reticulum ◽  
Transmission Electron Microscope ◽  
Electron Microscopic ◽  
Cardiac Sarcoplasmic Reticulum ◽  
Transmission Electron

Cardiac sarcoplasmic reticulum (SR) is a complex system of intracellular tubules that, due to their small size and juxtaposition to such electron-dense structures as mitochondria and myofibrils, are often inconspicuous in conventionally prepared electron microscopic material. This study reports a method with which the SR is selectively “stained” which facilitates visualizationwith the transmission electron microscope.

Surface Structure of the Spores of Glugea Weissenbergi

1969 ◽  
Vol 27 ◽  
pp. 238-239
Author(s):  
Sanford H. Vernick ◽  
Anastasios Tousimis ◽  
Victor Sprague
Keyword(s):  
Electron Microscope ◽  
Surface Structure ◽  
Transmission Electron Microscope ◽  
Mature Spore ◽  
Spore Surface ◽  
Sectioned Material ◽  
Transmission Electron ◽  
Surface Detail

Recent electron microscope studies have greatly expanded our knowledge of the structure of the Microsporida, particularly of the developing and mature spore. Since these studies involved mainly sectioned material, they have revealed much internal detail of the spores but relatively little surface detail. This report concerns observations on the spore surface by means of the transmission electron microscope.

A New High Resolution Transmission Electron Microscope with Second-Zone Objective Lens

1969 ◽  
Vol 27 ◽  
pp. 176-177 ◽  
Author(s):  
H. Tochigi ◽  
H. Uchida ◽  
S. Shirai ◽  
K. Akashi ◽  
D. J. Evins ◽  
...  
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Transmission Electron Microscope ◽  
Objective Lens ◽  
High Excitation ◽  
Transmission Electron ◽  
New Instrument

A New High Excitation Objective Lens (Second-Zone Objective Lens) was discussed at Twenty-Sixth Annual EMSA Meeting. A new commercially available Transmission Electron Microscope incorporating this new lens has been completed.Major advantages of the new instrument allow an extremely small beam to be produced on the specimen plane which minimizes specimen beam damages, reduces contamination and drift.

X-ray microanalysis of thin specimens in the transmission electron microscope at voltages up to 1000 Kv.

1978 ◽  
Vol 36 (1) ◽  
pp. 540-541
Author(s):  
G. Cliff ◽  
M.J. Nasir ◽  
G.W. Lorimer ◽  
N. Ridley
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Weight Fraction ◽  
Present Series ◽  
Constant Independent ◽  
X Ray ◽  
Transmission Electron ◽  
Series Of Experiments ◽  
Image Position ◽  
X Ray Absorption

In a specimen which is transmission thin to 100 kV electrons - a sample in which X-ray absorption is so insignificant that it can be neglected and where fluorescence effects can generally be ignored (1,2) - a ratio of characteristic X-ray intensities, I1/I2 can be converted into a weight fraction ratio, C1/C2, using the equationwhere k12 is, at a given voltage, a constant independent of composition or thickness, k12 values can be determined experimentally from thin standards (3) or calculated (4,6). Both experimental and calculated k12 values have been obtained for K(11<Z>19),kα(Z>19) and some Lα radiation (3,6) at 100 kV. The object of the present series of experiments was to experimentally determine k12 values at voltages between 200 and 1000 kV and to compare these with calculated values.The experiments were carried out on an AEI-EM7 HVEM fitted with an energy dispersive X-ray detector.

Aspects of microanalysis in a transmission electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 510-511
Author(s):  
R. Sinclair ◽  
B.E. Jacobson
Keyword(s):  
Grain Size ◽  
Electron Beam ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Transmission Electron Microscope ◽  
Vapor Deposition ◽  
Critical Currents ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron

INTRODUCTIONThe prospect of performing chemical analysis of thin specimens at any desired level of resolution is particularly appealing to the materials scientist. Commercial TEM-based systems are now available which virtually provide this capability. The purpose of this contribution is to illustrate its application to problems which would have been intractable until recently, pointing out some current limitations.X-RAY ANALYSISIn an attempt to fabricate superconducting materials with high critical currents and temperature, thin Nb3Sn films have been prepared by electron beam vapor deposition [1]. Fine-grain size material is desirable which may be achieved by codeposition with small amounts of Al2O3 . Figure 1 shows the STEM microstructure, with large (∽ 200 Å dia) voids present at the grain boundaries. Higher quality TEM micrographs (e.g. fig. 2) reveal the presence of small voids within the grains which are absent in pure Nb3Sn prepared under identical conditions. The X-ray spectrum from large (∽ lμ dia) or small (∽100 Ǻ dia) areas within the grains indicates only small amounts of A1 (fig.3).

The direct determination of magnetic domain wall profiles using a split detector STEM

1978 ◽  
Vol 36 (1) ◽  
pp. 466-467
Author(s):  
J.N. Chapman ◽  
P.E. Batson ◽  
E.M. Waddell ◽  
R.P. Ferrier
Keyword(s):  
Electron Microscope ◽  
Domain Wall ◽  
Transmission Electron Microscope ◽  
Domain Walls ◽  
Photographic Plate ◽  
Magnetic Domain ◽  
Direct Determination ◽  
Quantitative Information ◽  
Scanning Transmission Electron Microscope ◽  
Transmission Electron

By far the most commonly used mode of Lorentz microscopy in the examination of ferromagnetic thin films is the Fresnel or defocus mode. Use of this mode in the conventional transmission electron microscope (CTEM) is straightforward and immediately reveals the existence of all domain walls present. However, if such quantitative information as the domain wall profile is required, the technique suffers from several disadvantages. These include the inability to directly observe fine image detail on the viewing screen because of the stringent illumination coherence requirements, the difficulty of accurately translating part of a photographic plate into quantitative electron intensity data, and, perhaps most severe, the difficulty of interpreting this data. One solution to the first-named problem is to use a CTEM equipped with a field emission gun (FEG) (Inoue, Harada and Yamamoto 1977) whilst a second is to use the equivalent mode of image formation in a scanning transmission electron microscope (STEM) (Chapman, Batson, Waddell, Ferrier and Craven 1977), a technique which largely overcomes the second-named problem as well.

A General Method for Spectrometer Design in the Scoff Approximation

1976 ◽  
Vol 34 ◽  
pp. 538-539
Author(s):  
J. R. Fields
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Energy Analysis ◽  
Incident Beam ◽  
Scanning Transmission Electron Microscope ◽  
Chemical Identification ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
General Method

The energy analysis of electrons scattered by a specimen in a scanning transmission electron microscope can improve contrast as well as aid in chemical identification. In so far as energy analysis is useful, one would like to be able to design a spectrometer which is tailored to his particular needs. In our own case, we require a spectrometer which will accept a parallel incident beam and which will focus the electrons in both the median and perpendicular planes. In addition, since we intend to follow the spectrometer by a detector array rather than a single energy selecting slit, we need as great a dispersion as possible. Therefore, we would like to follow our spectrometer by a magnifying lens. Consequently, the line along which electrons of varying energy are dispersed must be normal to the direction of the central ray at the spectrometer exit.

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