Slip Transition in [001] Oriented Nial at High Temperatures

1990 ◽  
Vol 213 ◽  
Author(s):  
J.T. Kim ◽  
R. Gibala
Keyword(s):  
Transition Temperature ◽  
Single Crystals ◽  
High Temperatures ◽  
Room Temperature ◽  
Effect Of Temperature ◽  
Slip Direction ◽  
Annealing Temperatures ◽  
The Stability ◽  
Slip Transition

ABSTRACTThe present work was undertaken to understand the transition in slip direction In [001] oriented NiAl as a function of temperature. Single crystals of [001] NiAl were deformed at room temperature to produce <111> dislocations and were subsequently annealed at various temperatures in order to see the effect of temperature on the stability of the <111> dislocation. These results were compared with corresponding dislocation substructures of specimens deformed directly at high temperatures. During annealing <111> dislocations are dissociated into <001>+<110> dislocations at 773–923 K. It is also observed that <111> dislocations can be dissociated into <001>+<110> dislocations during deformation in the vicinity of the transition temperature of around 773 K. The quantitative details of these changes depend on deformation or annealing temperatures.

Interaction of Copper Film with Silicides

1990 ◽  
Vol 181 ◽  
Author(s):  
Yow-Tzong Shy ◽  
Shyam P. Murarka ◽  
Carlton L. Shepard ◽  
William A. Lanford
Keyword(s):  
Sheet Resistance ◽  
Diffusion Barrier ◽  
Room Temperature ◽  
Copper Film ◽  
Furnace Annealing ◽  
Rutherford Back Scattering ◽  
Annealing Temperatures ◽  
Back Scattering ◽  
The Stability ◽  
Stable Structures

ABSTRACTBilayers of Cu with TiSi2 and TaSi2 were tested by furnace annealing at temperatures from 200 to 500°C. Rutherford Back Scattering (RBS) technique was used to investigate the interaction between various films and determine the stability of Cu on silicide structures. The sheet resistance was also monitored. The results show that Cu on TiSi2 and TaSi2 structures are extremely stable structures at annealing temperatures in the range of room temperature to 500 °C. In such structures, therefore, there will not be a need of any diffusion barrier between Cu and the silicide films.

scholarly journals The Stability of Icosahedral Cd-Yb

2003 ◽  
Vol 805 ◽  
Author(s):  
Günter Krauss ◽  
Sofia Deloudi ◽  
Andrea Steiner ◽  
Walter Steurer ◽  
Amy R. Ross ◽  
...  
Keyword(s):  
Low Temperature ◽  
Ambient Temperature ◽  
Mechanical Stress ◽  
Single Crystals ◽  
High Temperatures ◽  
Low Temperatures ◽  
Ambient Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Stability

ABSTRACTThe stability of single-crystalline icosahedral Cd-Yb was investigated using X-ray diffraction methods in the temperature range 20 K ≤ T ≤ 900 K at ambient pressure and from ambient temperature to 873 K at about 9 GPa. Single-crystals remain stable at low temperatures and in the investigated HP-HT-regime. At high temperatures and ambient pressure, the quasicrystal decomposes. The application of mechanical stress at low temperatures yields to the same decomposition, the formation of Cd. A reaction of icosahedral Cd-Yb with traces of oxygen or water causing the decomposition seems reasonable, but a low-temperature instability of this binary quasi-crystal cannot be ruled out totally.

Ion Induced Damage and their Annealing in LiTaO3 Single Crystal

1995 ◽  
Vol 396 ◽  
Author(s):  
Z Zhang ◽  
I.A. Rusakova ◽  
W.K. Chu
Keyword(s):  
Curie Temperature ◽  
Single Crystal ◽  
Single Crystals ◽  
Thermal Annealing ◽  
Crystalline Structure ◽  
Room Temperature ◽  
Complete Recovery ◽  
Oxygen Ions ◽  
Annealing Temperatures ◽  
Crystal Interface

AbstractLiTaO3 single crystals have been implanted with 100 keV oxygen ions at room temperature with doses of 1×1014 /cm2,6xl014/cm2,1.2x1015/cm2, 6xl015/cm2, and 2xl016/cm2. Annealing temperatures ranged from 550 °C to 1075 °C. RBS-channeling and TEM were used for characterization. For partially damaged samples, complete recovery of the crystalline structure was achieved after annealing at 550 °C, which is below the Curie temperature. For totally amorphized samples, thermal annealing induced multidomain growth. These domains extend beyond the original amorphous/crystal interface deep into bulk (1 – 1.5 μm ).

Feedback Controlled Bilayer Heating Within the Regulated Attachment Method

2013 ◽  
Author(s):  
Graham Taylor ◽  
Andy Sarles
Keyword(s):  
Feedback Control ◽  
Lipid Bilayers ◽  
Room Temperature ◽  
Open Loop ◽  
Effect Of Temperature ◽  
Transient Temperature ◽  
Electrical Measurements ◽  
Power Inputs ◽  
Heating Model ◽  
The Stability

Synthetic lipid bilayers provide a cell-inspired environment for studying the functions of biomolecules. The regulated attachment method (RAM) is one method for forming liquid-supported lipid bilayers — known as droplet interface bilayers (DIBs) — that form at the interface of lipid-encased aqueous volumes in oil. While RAM allows for independent control of the aqueous phases on both sides of the membrane and provides a convenient way to control the size of the bilayer, previous studies utilizing this technique have been performed exclusively at room temperature. The goal of this research is to incorporate proportional-integral (PI) feedback control of temperature within the flexible RAM substrate with initial efforts focused on heating above room temperature. The proposed system includes a resistive etched-foil heating element and wire-type thermocouples for point-wise temperature measurement in standard RAM substrates. Open loop heating tests are used to map the magnitudes of steady state temperature distributions within the substrate and characterize the dynamic heating response. These tests show that a first-order heating model accurately describes transient temperature responses to heater power inputs. A one-probe configuration is found to provide measurements that are within <1°C of temperature measured at the bilayer region. The optimized probe configuration is used in PI feedback control, where the closed loop system is found to track the desired temperature to within +/−0.3°C. Experiments of temperature control with aqueous lipid droplets present permit electrical measurements of bilayer area without increasing background noise. Using this platform, we study the effect of temperature on the stability and size of a diphytanoyl phosphatidylcholine (DPhPC) lipid bilayer, and we observe that increasing the temperature of the bilayer from room temperature to 30°C results in a 30% decrease in the area of the membrane.

FEM and FIM Study of Reaction Zones on Platinum

1997 ◽  
Vol 62 (2) ◽  
pp. 213-217
Author(s):  
Zlatko Knor ◽  
Jan Plšek ◽  
Luboš Dvořák
Keyword(s):  
Temperature Field ◽  
Low Temperature ◽  
Single Crystals ◽  
Room Temperature ◽  
Effect Of Temperature ◽  
Surface Anisotropy ◽  
Initial Shape ◽  
Reaction Zones

The initial shape of the reaction zones for the interaction of hydrogen and oxygen on the surfaces of the single crystals of platinum in FEM and FIM devices is discussed in connection with the effect of temperature and surface anisotropy. Interaction of the (H2 + O2) mixture has been studied at room temperature and the results were confronted with the interaction of hydrogen and preadsorbed oxygen at low temperature and with the anisotropy of the low-temperature field-corrosion of platinum.

Light Absorption by Pyrene Single Crystals Between 4 and 300 °K

1973 ◽  
Vol 28 (6) ◽  
pp. 973-979 ◽  
Author(s):  
D. Fischer ◽  
G. Naundorf ◽  
W. Klöpffer
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Single Crystals ◽  
Absorption Edge ◽  
Ground State ◽  
Light Absorption ◽  
Room Temperature ◽  
Polarized Light ◽  
Equilibrium Distance ◽  
Exciton Transport

Pyrene single crystals have been grown from zone refined material by sublimation and from the melt. The absorption edge has been measured for thick and thin crystals at room temperature. Thin crystals have been successfully cooled below the phase transition temperature (123 °K) without cracking. The sharp absorption peak at 376 nm vanishes at this temperature while the fluorescence spectrum remains unchanged. Using polarized light below 50 °K, a band with a maximum at 410 nm appears whose intensity increases with decreasing temperature. It is concluded that this band is due to ground-to-excimer state absorption in the ground state equilibrium distance of the pyrene molecules. The consequences of this finding for excimer-exciton transport is discussed.

Effects of Deviation from Stoichiometry on Deformation Behavior of Hard-Oriented NiAl Single Crystals

1998 ◽  
Vol 552 ◽  
Author(s):  
R. Srinivasan ◽  
M. F. Savage ◽  
R. D. Noebe ◽  
M. J. Mills
Keyword(s):  
Transition Temperature ◽  
Single Crystals ◽  
Deformation Behavior ◽  
Mechanical Response ◽  
Slip Systems ◽  
Alloying Additions ◽  
Strain And Strain Rate ◽  
Deviation From Stoichiometry ◽  
Slip Transition ◽  
Active Slip

ABSTRACTNi-44A1, Ni-50Al and NiAl-0.3 at.% Hf single crystals have been studied in compression to understand the effects that alloying additions and deviation from stoichiometry can have on the mechanical response of NiAl-based single crystals. While all three single crystals deform through a<111> slip at lower temperatures, the active slip systems differ at higher temperatures. Climb of a<010> dislocations contributes to deformation in Ni-50AI single crystals beyond the slip transition temperature, while Ni-44Al and NiAl-0.3Hf crystals deform through a<101> glide. But several microstructural differences have been observed in the mode of deformation between Ni-44Al and NiAl-0.3Hf crystals. In addition, significant strengthening is exhibited in the Hf-doped crystals at higher temperatures. The post-deformation microstructure is also observed to be sensitive to both strain and strain rate. A possible explanation is offered for some of the observed differences in deformation behavior between the three alloys.

Temperature dependence of piezoelectric properties of 0.67 Pb(Mg1/3Nb2/3)O3–0.33 PbTiO3 single crystals

2003 ◽  
Vol 18 (2) ◽  
pp. 537-541 ◽  
Author(s):  
Ping-chu Wang ◽  
Xiao-ming Pan ◽  
Dong-lin Li ◽  
Yuan-wei Song ◽  
Hao-su Luo ◽  
...  
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Phase Transition Temperature ◽  
Room Temperature ◽  
Piezoelectric Properties ◽  
Device Design ◽  
Temperature Range ◽  
Approach Zero

Piezoelectric properties k33 and d33 of 0.67 Pb(Mg1/3Nb2/3)O3–0.33 PbTiO3 single crystals grown by a modified Bridgman method were measured in the temperature range of 20–150 °C. Recoverability of the properties after the samples were heated to 110 °C, above the ferroelectric–ferroelectric (F–F) phase transition temperature of the composition, was found. From 20 to approximately 80 °C, k33 increases slightly, while d33 is almost doubled. Between approximately 90 and 100 °C, k33 decreases sharply to roughly a level of PZT-5 ceramics and d33 decreases to about 700 pC/N. They increase again with further increase of temperature; at 140 °C they attain 0.74 and approximately 1300 pC/N, respectively, and then decrease quickly and approach zero at about 150 °C. When heating to 110 °C followed by cooling to room temperature, the property decay is small. After more than one dozen heating–cooling cycles, k33 and d33 tend to be stable at 0.89 and approximately 1220 pC/N, respectively. The results might be helpful for device design and applications of PMN–PT single crystals.

THERMOPOWER ANISOTROPY OF YBa2Cu3O7−δ SINGLE CRYSTALS

1989 ◽  
Vol 03 (03) ◽  
pp. 409-413 ◽  
Author(s):  
SHU-YUAN LIN ◽  
LI LU ◽  
HONG-MIN DUAN ◽  
BEI-HAI MA ◽  
DIAN-LIN ZHANG
Keyword(s):  
Transition Temperature ◽  
Single Crystals ◽  
Superconducting Transition Temperature ◽  
Room Temperature ◽  
Superconducting Transition ◽  
Strong Anisotropy ◽  
Metallic Behavior

The thermopower of YBa 2 Cu 3 O 7−δ single crystals has been measured from 300 K down to superconducting transition temperature. Strong anisotropy was observed. While the thermopower along ab-plane slightly increased with decreasing temperature, reaching 5 ~ 8 μ V/K around 120 K, the thermopower along c-axis showed typical metallic behavior with room temperature value as large as ~ 30 μ V/K .

Fabrication and thermal stability of a nanocrystalline Ni–Al–Cr alloy: Comparison with pure Cu and Ni

1999 ◽  
Vol 14 (11) ◽  
pp. 4200-4207 ◽  
Author(s):  
Keiichiro Oh-ishi ◽  
Zenji Horita ◽  
David J. Smith ◽  
Ruslan Z. Valiev ◽  
Minoru Nemoto ◽  
...  
Keyword(s):  
Grain Size ◽  
Room Temperature ◽  
Negative Slope ◽  
Annealing Temperatures ◽  
Grain Sizes ◽  
Lattice Distortions ◽  
The Stability ◽  
Highly Strained ◽  
Pure Cu ◽  
Thermal Stability Of

A Ni–Al–Cr alloy with an initial grain size of ∼60 μm was subjected to torsion straining to a strain of ∼7 at room temperature, thereby reducing the grain size to ∼34 nm. Similar torsion straining with samples of pure Cu and pure Ni gave grain sizes of ∼170 and ∼130 nm, respectively. Inspection of the Ni–Al–Cr alloy after torsion straining revealed highly strained regions containing dislocations associated with lattice distortions but with an absence of any Ni3Al ordered phase. The ultrafine grains in the Ni–Al–Cr alloy were extremely stable at high temperatures, and it was possible to retain a grain size of less than 100 nm after annealing at temperatures up to ∼900 K. By contrast, there was rapid grain growth in the samples of pure Cu and Ni at annealing temperatures in the vicinity of ∼500 K. The stability of the grains in the Ni–Al–Cr alloy is attributed to the formation of a Ni3Al-based ordered phase after annealing at ∼650–700 K. The presence of this phase also leads to an apparent negative slope in the standard Hall–Petch relationship.

Sign in / Sign up

Export Citation Format

Share Document