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Displaying 51 - 75 of 1279

Shape of Hollow Dislocation Cores: Elastic and Anisotropic Surface Energy Effects

October 12, 2021
Author(s)
David J. Srolovitz, N Sridhar, J P. Hirth, John W. Cahn
Evidence for the existence of hollow core dislocations has existed for nearly forty years. Such hollow cores are often found in growth spirals associated with screw dislocations. Examples of this type of morphology may be found in silicon carbide, copper

Simulating Thermal Response of EB-PVD Thermal Barrier Coating Microstructures

October 12, 2021
Author(s)
M Bartsch, U Schulz, J M. Dorvaux, O Lavigne, Lin-Sien H. Lum, Stephen A. Langer
As ceramic thermal barrier coatings (TBC) are used in more critical applications in advanced engines, knowing basic physiproperties of TBC's is essential for design and reliability assessment. In particular, knowledge of thermal conductivity is cruciin

Simulation of a Single Asperity Impacts at Head-Disk Interface

October 12, 2021
Author(s)
Tze J. Chuang, Stephen M. Hsu
During the track accessing mode of a hard disk drive, the flying height of the slider over the disk surface becomes smaller and smaller as the demand in data storage a real density increases. As a result, the propensity of glide avalanche is bound to

SiO 2 /Si 3 N 4 /A1 2 O 3 Stacks on Silicon for Scaled-Down Memory Devices: Effects of Interfaces and Thermal Annealing

October 12, 2021
Author(s)
M Lisiansky, A Heiman, M Kovler, Y Roizin, Igor Levin, A Gladkikh, M Oksman, R Edrei, A A. Hofman, Y Shnieder, T Claasen
Effects of interfaces and thermal annealing on the electrical performance of the SiO2/Si3N4/A12O3 (ONA) stacks in non-volatile memory devices were investigated. Structural and electrical characterization demonstrated the principal role of the Si3N4/A12O3

Solidus Phase Relationships in the AO-Al 2 O 3 -Nb 2 O 5 (A = Ca, Sr) Systems

October 12, 2021
Author(s)
Julia Y. Chan, Wilma Feb-Ayala, L D. Rotter, Igor Levin, Richard G. Geyer
Dielectric ceramics for wireless communications exhibiting modest permittivity, high quality factor (Q), and near-zero temperature coefficient are needed for high frequency, high power applications. Efforts are in progress to replace Ta2O5-based ceramics

Stoichiometry and Phase Composition of MOCVD Barium Titanate Films

October 12, 2021
Author(s)
Charles E. Bouldin, Joseph Woicik, Bruce Ravel, Debra Kaiser, Mark D. Vaudin
X-ray absorption fine structure (XAFS), x-ray diffraction (XRD) and x-ray fluorescence (XRF) have been used to study the stoichiometry and phase composition of thin (approximately equal to} 1 micron) films deposited on MgO substrates. Deposition

Strength Evaluation on a Composite Marine Propeller Blade

October 12, 2021
Author(s)
H J. Lin, J J. Lin, Tze-Jer Chuang
The strength of a composite propeller blade is evaluated by performing a nonlinear hydro-elastic analysis. The finite element method, lifting surface theory, least square method, equilibrium equation and Hashin failure criteria are employed for the

Structure and Crystal Chemistry of M 0.5 Ta 0.5 B (M = Ti, Zr, and Hf)

October 12, 2021
Author(s)
I Talmy, J Zaykoski, J A. Kudak, Winnie Wong-Ng
During the development of refractory composites (cermets) combining MB2 (M=Ti, Zr, or Hf) ceramics and Ta metal, three new phases of compositions M0.5Ta0.5B were discovered. Preliminary determination of lattice parameters using x-ray powder diffraction

Subsolidus Phase Relationships in the AO-AI 2 O 3 -Nb 2 O 5 (A=Ca, Sr) Systems

October 12, 2021
Author(s)
Julia Y. Chan, Wilma Feb-Ayala, J. M. Loezos, L D. Rotter, Lyle E. Levine, Richard G. Geyer
Dielectric ceramics for wireless communications exhibiting modest permittivity, high quality factor (Q), and near-zero temperature coefficient are needed for high-frequency, high power applications. Efforts are in progress to replace Ta2O5-based ceramics

Surface Energy Anisotropy of SrTiO 3 at 1400 C in Air

October 12, 2021
Author(s)
T Sano, D M. Saylor, G S. Rohrer
Geometric and crystallographic measurements of grain boundary thermal grooves and surface faceting behavior as a function of orientation have been used to determine the surface energy anisotropy of SrTiO3 at 1400 C in air. Under these conditions, thermal

Surface Morphology Dependent Magnetic Thin Film Growth: Fe on GaN(0001)

October 12, 2021
Author(s)
P Ryan, R A. Rosenberg, D J. Keavney, J W. Freeland, Joseph Woicik
Iron deposition on ordered and disordered GaN (0001) surfaces result in dramatically different magnetic over-layer characteristics. On the ordered surface, nitrogen rapidly desorbs upon Fe deposition and a magnetically disordered film is produced

Synchrotron Based Surface Science to Probe Polymeric Interfacial Regions

October 12, 2021
Author(s)
Joseph~undefined~undefined~undefined~undefined~undefined Lenhart, Daniel A. Fischer
Synchrotron based X-ray absorption spectroscopy was utilized to probe the chemistry and structure of polymers in interfacial regions, including the interfacial regions, including the interfacial composition of filled epoxy composites, and the surface

Tailoring the High-K Gate Dielectric/Sillicon Interface for CMOS Applications

October 12, 2021
Author(s)
Y S. Lin, R Puthenkovilakam, J P. Chang, C P. Bouldin, Igor Levin, Nhan Van Nguyen, Y Sun, P Pianetta, T Conard, W Vandervorst, V Venturo, S Selbrede
The interfacial properties, thermal stabilities, and the electrical characteristics of ZrO2/ Si and ZrO2/SiO2/Si were investigated and the interfacial layer of as-deposited ZrO2 on silicon is likely to be ZrSixOy. The ZrO2/ZrSixOy/Si is stoichiometic

The Crystal Chemistry of L-Ta 2 O 5 and Related Structures

October 12, 2021
Author(s)
I E. Grey, W G. Mumme, Robert S. Roth
Single crystals of a new form of L-Ta2O5 with a 19 x b superstructure have been synthesised by flux growth. The phase has C-centred monoclinic symmetry with a = 6.199(1) , b = 69.55(1) (= 19 x 3.66 ), c = 3.880 (1) . The structure was refined in space

The Nanostructure Problem

October 12, 2021
Author(s)
Simon J. Billinge, Igor Levin
The powerful methods we have for solving the atomic structure of bulk crystals fail for nanostructured materials and there are currently no broadly applicable, quantitative and robust methods to replace them. The solution of this nanostructure problem is

Theory of Strain Percolation in Metals

October 12, 2021
Author(s)
R Thomson, Lyle E. Levine
We demonstrate that a deforming metal is a self organizing critical system, and that the stress-strain law can be expressed as an integration of certain derivatives of internal variables along the critical line of the system.
Displaying 51 - 75 of 1279