A High Voltage Electron Microscopy Study of Sub-Oxide Formation in Vanadium

1971 ◽  
Vol 29 ◽  
pp. 212-213
Author(s):  
R. H. Geiss ◽  
R. L. Ladd ◽  
K. R. Lawless
Keyword(s):  
High Vacuum ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Ultra High Vacuum ◽  
Pure Oxygen ◽  
Pressure Oxidation ◽  
High Voltage Electron Microscopy ◽  
Oxidation Study ◽  
Voltage Electron ◽  
Good Agreement

Detailed electron microscope and diffraction studies of the sub-oxides of vanadium have been reported by Cambini and co-workers, and an oxidation study, possibly complicated by carbon and/or nitrogen, has been published by Edington and Smallman. The results reported by these different authors are not in good agreement. For this study, high purity polycrystalline vanadium samples were electrochemically thinned in a dual jet polisher using a solution of 20% H2SO4, 80% CH3OH, and then oxidized in an ion-pumped ultra-high vacuum reactor system using spectroscopically pure oxygen. Samples were oxidized at 350°C and 100μ oxygen pressure for periods of 30,60,90 and 160 minutes. Since our primary interest is in the mechanism of the low pressure oxidation process, the oxidized samples were cooled rapidly and not homogenized. The specimens were then examined in the HVEM at voltages up to 500 kV, the higher voltages being necessary to examine thick sections for which the oxidation behavior was more characteristic of the bulk.

Observations on Developing Blood Vessels in Rat Spinal Cord—A High Voltage Electron Microscopy Study

1974 ◽  
Vol 32 ◽  
pp. 66-67
Author(s):  
Richard S. Hannah
Keyword(s):  
Electron Microscopy ◽  
Spinal Cord ◽  
High Voltage ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
High Voltage Electron Microscopy ◽  
Thin Sections ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Transmission Electron

The formation of junctional complexes between endothelial cell processes was examined in rat spinal cords, from age birth to six weeks. Segments of spinal cord were removed from the region of the cervical enlargement and fixed. For comparative purposes, animals from each time group were subdivided into groups, fixed by either immersion or perfusion with an aldehyde combination in sodium cacodylate buffer and embedded in Araldite. Thin sections were examined by conventional transmission electron microscopy. Thick sections (0.5μ - 1.0μ) were stained with uranyl magnesium acetate for four hours at 60°C and lead citrate for 30 mins. and examined in the AEI Mark II High Voltage Electron Microscope.

UHV Electron Microscopy study of in situ annealed (100) surfaces of MgO

1991 ◽  
Vol 49 ◽  
pp. 624-625
Author(s):  
M. Gajdardziska-Josifovska ◽  
M. R. McCartney ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Surface Characterization ◽  
High Vacuum ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Ultra High Vacuum ◽  
Frequent Use ◽  
Reflection Electron Microscopy ◽  
Catalyst Systems

The (100) surface of magnesium oxide is of considerable interest because of its frequent use as substrate for epitaxial growth of metal films, high Tc superconductors and model catalyst systems. A large number of surface characterization techniques have been used to determine the atomic structure of the cleaved (100) surface. Clean surfaces have been produced either by cleaving MgO crystals in-situ under ultra-high vacuum (UHV) conditions, or more frequently, by cleaving in air and subsequent annealing in UHV. A wide variety of annealing temperatures and times have been used by different researchers, the upper limit on the temperature being set at ≈900°C to avoid segregation of Ca to the surface. Calcium is the main impurity in even the purest MgO crystals and a few studies have dealt with the structure of the Ca-rich (100) surface of MgO. All of the existing studies have used diffraction and spectroscopy techniques without imaging of the surface. It is the purpose of this work to study the topography of the UHV-annealed (100) surface by reflection electron microscopy (REM).

Ultra High Voltage Electron Microscopy Study of {113}-Defect Generation in Si Nanowires

2014 ◽  
Vol 1713 ◽  
Author(s):  
J. Vanhellemont ◽  
S. Anada ◽  
T. Nagase ◽  
H. Yasuda ◽  
H. Bender ◽  
...  
Keyword(s):  
High Voltage ◽  
Defect Formation ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Intrinsic Point Defect ◽  
Si Nanowires ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Ultra High Voltage

ABSTRACTResults are presented of a study of {113}-defect formation in Si nanowires with diameters ranging from 50 to 500 nm. The Si nanowires, used for the processing of tunnel-FET's, are etched into a moderately doped epitaxial Si layer on a heavily doped n-type Si substrate. {113}- defects are created in situ by 2 MeV e-irradiation at temperatures between room temperature and 375 °C in an ultra high voltage electron microscope. The observations are discussed in the frame of intrinsic point defect out-diffusion and interaction with dopant atoms.

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