Surface and Bulk Diffusion of H218O on Single-Crystal H216O Ice Multilayers

1996 ◽  
Vol 100 (38) ◽  
pp. 15460-15469 ◽  
Author(s):  
D. E. Brown ◽  
S. M. George
Keyword(s):  
Single Crystal ◽  
Bulk Diffusion

Surface and bulk diffusion of HDO on ultrathin single-crystal ice multilayers on Ru(001)

1998 ◽  
Vol 108 (5) ◽  
pp. 2197-2207 ◽  
Author(s):  
Frank E. Livingston ◽  
Galen C. Whipple ◽  
Steven M. George
Keyword(s):  
Single Crystal ◽  
Bulk Diffusion

Electromigration Lifetimes of Single Crystal Aluminum Lines with Different Crystallographic Orientations

1994 ◽  
Vol 338 ◽  
Author(s):  
Y.-C. Joo ◽  
C.V. Thompson
Keyword(s):  
Activation Energy ◽  
Single Crystal ◽  
Diffusion Mechanism ◽  
Failure Mechanisms ◽  
Bulk Diffusion ◽  
Time To Failure ◽  
Interface Diffusion ◽  
Test Conditions ◽  
Service Conditions ◽  
Crystallographic Orientations

ABSTRACTNear-bamboo interconnects are susceptible to failure either at polygranular clusters or within bamboo grains (transgranular failure). Polygranular failure mechanisms are often dominant in lines with near-bamboo structures at test conditions, but at service conditions, transgranular failure mechanisms are expected to dominate. In order to study the temperature and current density dependence as well as the crystallographic dependence of these transgranular failure mechanisms, it is necessary to isolate them from other mechanisms. To do this, we have studied single crystal Al lines on oxidized silicon.We have tested lifetimes of passivated and unpassivated Al single crystal lines with various textures. In both passivated and unpassivated lines, the median time to failure, t50, was found to be texture-dependent, with t50(l11) > t50(133) > t50(110), and with t50(111) ∼ 10×t50(110). The activation energy for failure for both passivated and unpassivated (110) single crystal lines was about 1 eV. This value differs from that of aluminum bulk diffusion (1.4 eV), suggesting that interface diffusion is the dominant diffusion mechanism in these lines, and perhaps in bamboo regions of near-bamboo lines as well.

Epitaxial Growth of MgO Single Crystal Thin Film in Oxygen Atmosphere

1992 ◽  
Vol 279 ◽  
Author(s):  
M. H. Yang ◽  
C. P. Flynn
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Epitaxial Growth ◽  
Bulk Diffusion ◽  
Oxygen Atmosphere ◽  
Mass Action ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffusion Studies ◽  
Mgo Substrate

ABSTRACTWe have studied the epitaxial growth of MgO single crystal thin films by depositing Mg onto MgO substrates in an oxygen atmosphere. This method provides a simple way to dope Mg18O layers uniformly into Mg16O. The well controlled layer thicknesses are suitable for bulk diffusion studies both in the MgO epilayer and the MgO substrate. The MgO growth rate was measured and found to be proportional to the Mg flux and to the square root of oxygen pressure at a given temperature, obeying the law of mass action. High quality MgO single crystal thin films, as indicated by RHEED and x-ray diffraction, were found to grow over u wide temperature range, as in the earlier work1 using e-beam evaporation.

scholarly journals A study of the initial stages of the electrochemical deposition of thallium on copper, Part IV. The potential step results: Underpotential deposition on (111), (110) and (100) oriented copper single c

2005 ◽  
Vol 3 (2) ◽  
pp. 157-168 ◽  
Author(s):  
Jovan Jovicevic ◽  
Alan Bewick
Keyword(s):  
Single Crystal ◽  
Bulk Diffusion ◽  
Underpotential Deposition ◽  
Crystal Formation ◽  
Formation Processes ◽  
Growth Step ◽  
Current Time ◽  
Single Crystal Surfaces ◽  
Potential Step ◽  
Response Characteristics

The underpotential deposition and dissolution of thallium onto carefully chemically polished single crystal copper (111), (110) and (100) electrode surfaces from acetate, sulphate and perchlorate solutions have been investigated using single and double potential step techniques. It appeared that the different anions used did not change the current-time response characteristics significantly. Current-time responses to the potential steps applied strongly resemble those observed in the case of thallium underpotential deposition on silver single crystals [1]. The characteristics of i-t transients obtained by single potential step suggest very fast 2D crystal growth processes taking place. Sharp linear voltammetry peaks, which are observed for both thallium and lead deposition on Cu(111) [3,8] and on Ag(111) [1,3], probably always indicate nucleative phase formation processes but the rate of the lattice growth step will vary from system to system. Comparison of the obtained results with those for lead underpotential deposition [8-13] on Cu(111), (110) and (100) suggests that, in the present case, the rate of the 2D lattice building process for both thallium underpotential monolayers formed on three copper single crystal surfaces examined is so fast that it becomes controlled by diffusive processes; this will probably be surface diffusion [24,25] initially and, at longer times planar bulk diffusion. Double pulse experiments did not help significantly in attempts to obtain i-t transients capable of providing data suitable for showing conclusively the occurrence of 2D crystal formation processes. A similar situation occurred also with silver substrates [1].

Cesium diffusion at a tungsten surface

1969 ◽  
Vol 47 (6) ◽  
pp. 657-663 ◽  
Author(s):  
H. M. Love ◽  
H. D. Wiederick
Keyword(s):  
Activation Energy ◽  
Diffusion Coefficient ◽  
Single Crystal ◽  
Surface Diffusion ◽  
Diffusion Processes ◽  
Bulk Diffusion ◽  
Photoelectric Method ◽  
Surface Diffusion Coefficient ◽  
Tungsten Surface ◽  
The Mean

The diffusion of cesium at the surface of tungsten ribbons has been measured under ultrahigh vacuum conditions. A photoelectric method was used to determine the cesium surface concentrations which were in the range from about 5 × 10−4 to 2 × 10−2 monolayers. The measured changes in concentration with time and temperature were consistent, for a polycrystalline ribbon, with two bulk diffusion processes with activation energies of 1.7 ± 0.3 eV and 0.17 ± 0.03 eV. For a single crystal, it was found that limited bulk diffusion occurred with an activation energy of 0.21 ± 0.02 eV. The mean surface diffusion coefficient for cesium on a (110) tungsten surface over the temperature range from 550 °K to 850 °K was given by D = (0.23 ± 0.10 cm2 s−1) exp [−(0.57 ± 0.02 eV)/kT].

scholarly journals Характерные закономерности конденсации слоев никеля на поверхности монокристалла вольфрама

2020 ◽  
Vol 46 (14) ◽  
pp. 47
Author(s):  
О.Л. Голубев
Keyword(s):  
External Field ◽  
Electric Field ◽  
Single Crystal ◽  
External Electric Field ◽  
Field Emission ◽  
Bulk Diffusion ◽  
Field Reconstruction ◽  
Wide Range ◽  
Field Emission Microscopy ◽  
Emission Microscopy

Using field emission microscopy methods , the condensation and adsorption of Ni from a fraction of monoatomic layer to several hundert layers on the surface of a single crystal W-tip over a wide range of surface temperatures T changes were studied. The adsorption Ni on W in contrast to the adsorption Si on W does not cause any reconstruction of the W-suface at any T of the surface, and there are also no phenomena of bulk diffusion and field reconstruction of the surface. When multi-layer coatings of Ni on the W-surface grow crystallites of Ni with its own structure and faceting at low T - on close-packed faces and at high T - on loose faces of W. The presence of strong external electric field makes it possible to keep the crystallites on the surface at temperatures much higher than their solute temperature in the absence of an external field.

Bulk Diffusion of Niobium in Single-Crystal Titanium Dioxide

2007 ◽  
Vol 111 (28) ◽  
pp. 8126-8130 ◽  
Author(s):  
Leigh R. Sheppard ◽  
Armand J. Atanacio ◽  
Tadeusz Bak ◽  
Janusz Nowotny ◽  
Kathryn E. Prince
Keyword(s):  
Titanium Dioxide ◽  
Single Crystal ◽  
Bulk Diffusion

A Preparation of High Resolution Standards for Electron Microscopy. Part II

1971 ◽  
Vol 29 ◽  
pp. 160-161
Author(s):  
Akira Tanaka ◽  
David F. Harling
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Carbon Black ◽  
Single Crystal ◽  
Dark Field ◽  
Graphitized Carbon Black ◽  
Graphitized Carbon ◽  
Dark Field Imaging ◽  
Crystal Films ◽  
Micro Holes

In the previous paper, the author reported on a technique for preparing vapor-deposited single crystal films as high resolution standards for electron microscopy. The present paper is intended to describe the preparation of several high resolution standards for dark field microscopy and also to mention some results obtained from these studies. Three preparations were used initially: 1.) Graphitized carbon black, 2.) Epitaxially grown particles of different metals prepared by vapor deposition, and 3.) Particles grown epitaxially on the edge of micro-holes formed in a gold single crystal film.The authors successfully obtained dark field micrographs demonstrating the 3.4Å lattice spacing of graphitized carbon black and the Au single crystal (111) lattice of 2.35Å. The latter spacing is especially suitable for dark field imaging because of its preparation, as in 3.), above. After the deposited film of Au (001) orientation is prepared at 400°C the substrate temperature is raised, resulting in the formation of many square micro-holes caused by partial evaporation of the Au film.

Structure of Palladium Single-Crystal Films Prepared by Flash Evaporation onto (001) NaCl Substrates

1970 ◽  
Vol 28 ◽  
pp. 456-457
Author(s):  
L. E. Murr ◽  
G. Wong
Keyword(s):  
Single Crystal ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
High Rate ◽  
Flash Evaporation ◽  
Optimum Load ◽  
Single Crystal Films ◽  
Crystal Films ◽  
A Current

Palladium single-crystal films have been prepared by Matthews in ultra-high vacuum by evaporation onto (001) NaCl substrates cleaved in-situ, and maintained at ∼ 350° C. Murr has also produced large-grained and single-crystal Pd films by high-rate evaporation onto (001) NaCl air-cleaved substrates at 350°C. In the present work, very large (∼ 3cm2), continuous single-crystal films of Pd have been prepared by flash evaporation onto air-cleaved (001) NaCl substrates at temperatures at or below 250°C. Evaporation rates estimated to be ≧ 2000 Å/sec, were obtained by effectively short-circuiting 1 mil tungsten evaporation boats in a self-regulating system which maintained an optimum load current of approximately 90 amperes; corresponding to a current density through the boat of ∼ 4 × 104 amperes/cm2.

Dislocations, Ordering and Antiferromagnetic Domains in MnO

1970 ◽  
Vol 28 ◽  
pp. 522-523
Author(s):  
D. J. Barber ◽  
R. G. Evans
Keyword(s):  
Electron Diffraction ◽  
Single Crystal ◽  
Optical Microscopy ◽  
Defect Chemistry ◽  
Magnetic Structures ◽  
Optically Transparent ◽  
Magnetic Features ◽  
Antiferromagnetic Domains

Manganese (II) oxide, MnO, in common with CoO, NiO and FeO, possesses the NaCl structure and shows antiferromagnetism below its Neel point, Tn∼ 122 K. However, the defect chemistry of the four oxides is different and the magnetic structures are not identical. The non-stoichiometry in MnO2 small (∼2%) and below the Tn the spins lie in (111) planes. Previous work reported observations of magnetic features in CoO and NiO. The aim of our work was to find explanations for certain resonance results on antiferromagnetic MnO.Foils of single crystal MnO were prepared from shaped discs by dissolution in a mixture of HCl and HNO3. Optical microscopy revealed that the etch-pitted foils contained cruciform-shaped precipitates, often thick and proud of the surface but red-colored when optically transparent (MnO is green). Electron diffraction and probe microanalysis indicated that the precipitates were Mn2O3, in contrast with recent findings of Co3O4 in CoO.

Sign in / Sign up

Export Citation Format

Share Document