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Displaying 26 - 50 of 196

Two-Dimensional Strain-Mapping by Electron Backscatter Diffraction and Confocal Raman Spectroscopy

November 27, 2017
Author(s)
Andrew J. Gayle, Lawrence Henry Friedman, Ryan Beams, Brian G. Bush, Yvonne B. Gerbig, Chris A. Michaels, Mark D. Vaudin, Robert F. Cook
The strain field surrounding a spherical indentation in silicon is mapped in two dimensions (2- D) using electron backscatter diffraction (EBSD) cross-correlation and confocal Raman spectroscopy techniques. The 200 mN indentation created a 4 m diameter

Strength of Brittle Materials in Moderately Corrosive Environments

October 30, 2017
Author(s)
Robert F. Cook
The strengths of four brittle materials―cordierite glass ceramic, fused silica, silicon, and polycrystalline alumina were measured after exposure to weakly-corrosive water and moderately- corrosive buffered HF (BHF) solution. Exposure to water did not

Quantitative Scanning Probe Microscopy for Nanomechanical Forensics

August 22, 2017
Author(s)
Frank W. DelRio, Robert F. Cook
Scanning probe microscopy techniques—in particular atomic force microscopy (AFM)—provide a means for imaging objects and measuring mechanical properties at the nano- and micro-scales in a non-destructive manner. In this paper, the previous use of AFM in

Blunt scratch strength of polycrystalline alumina

August 21, 2017
Author(s)
Robert F. Cook
A model for the fracture strength of brittle materials controlled by blunt (spherical) scratches is developed and compared with measurements on a polycrystalline alumina. The model is based on a residual stress-intensity factor for median cracks at

Near-theoretical fracture strengths in native and oxidized silicon nanowires

June 21, 2016
Author(s)
Frank W. DelRio, Ryan M. White, Sergiy Krylyuk, Albert Davydov, Lawrence H. Friedman, Robert F. Cook
In this letter, fracture strengths σf of native and oxidized silicon nanowires (SiNWs) were determined via atomic force microscopy bending experiments and nonlinear finite element analysis. In the native SiNWs, σf in the Si was comparable to the

Stochastic behavior of nanoscale dielectric wall buckling

March 16, 2016
Author(s)
Lawrence H. Friedman, Igor Levin, Robert F. Cook
The random buckling patterns of nanoscale dielectric walls are analyzed using a nonlinear multi-scale stochastic method that combines experimental measurements with simulations. The dielectric walls, approximately 200 nm tall and 20 nm wide, consist of