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Search Publications by: Bob R. Keller (Fed)

Displaying 26 - 50 of 91

Dark-Field Image Contrast in Transmission Scanning Electron Microscopy: Effects of Substrate Thickness and Detector Collection Angle

August 6, 2016

Author(s)

Taylor J. Woehl, Robert R. Keller

An annular dark field (ADF) detector was placed beneath a specimen in a field emission scanning electron microscope operated at 30 kV to calibrate detector response to incident beam current, and to create transmission images of gold nanoparticles on

Detection of Atomic Force Microscopy Cantilever Displacement with a Transmitted Electron Beam

July 29, 2016

Author(s)

Ryan B. Wagner, Taylor J. Woehl, Robert R. Keller, Jason P. Killgore

Cantilever motion in atomic force microscopy (AFM) systems is typically measured with an optical lever system. The response time of AFM cantilevers can be decreased by reducing the size of the cantilever; however, the fastest AFM cantilevers are currently

Angularly-Selective Transmission Imaging in a Scanning Electron Microscope

May 5, 2016

Author(s)

Jason D. Holm, Robert R. Keller

This contribution presents recent advances in imaging control conditions for transmission scanning electron microscopy (t-SEM) by means of angularly-selective electron collection with a commercial scanning transmission electron microscopy-in-scanning

Firearm Serial Number Restoration with Electron Backscatter Diffraction

September 23, 2015

Author(s)

Ryan White, Robert Keller

N/A (manuscript is abstract)

An Analytical Scattering Model for Low Energy Annular Dark Field Transmission Scanning Electron Microscopy

September 22, 2015

Author(s)

Taylor J. Woehl, Jason D. Holm, Robert R. Keller

Here we employ an analytical electron scattering model to show that the decrease in ADF t-SEM contrast of gold nanoparticles on carbon films is consistent with a competition between mass-thickness and atomic number contrast. Images of gold nanoparticles on

Analytical Transmission Scanning Electron Microscopy: Extending the Capabilities of a Conventional SEM Using an Off-the-Shelf Transmission Detector

August 6, 2015

Author(s)

Jason Holm, Bob R. Keller

This work demonstrates how a modular transmission detector can be used to extend the analytical capabilities of a conventional SEM. By implementing a new sample holder and aperture system, we show that high angle and other dark field imaging techniques are

Beam broadening in transmission EBSD

March 16, 2015

Author(s)

Robert R. Keller, Katherine P. Rice, Mark Stoykovich

Transmission electron backscatter diffraction (t-EBSD), also known as transmission electron forward scatter diffraction (t-EFSD) or transmission Kikuchi diffraction in the SEM (TKD-SEM), can provide significant improvements in spatial resolution over

Restoration of firearm serial numbers with electron backscatter diffraction (EBSD)

February 9, 2015

Author(s)

Ryan White, Robert Keller

Firearm serial numbers are a critical identifying mark, and restoration of destroyed serial numbers is often crucial for prosecution of a criminal case. Currently available methods, including acid etching and relief polishing, present serious limitations

Specimen-thickness effects on transmission Kikuchi patterns in the scanning electron microscope

March 24, 2014

Author(s)

Katherine P. Rice, Robert R. Keller, Mark Stoykovich

We report the effects of varying specimen thickness onthe generation of transmission Kikuchi patterns in the scanning electron microscope. Diffraction patterns sufficient for automated indexing were observed from films spanning nearly three orders of

New Measurements on the Minimum and Maximum Sample Sizes in t-EBSD

October 9, 2013

Author(s)

Roy H. Geiss, Robert R. Keller, Katherine P. Rice

The technique of acquiring transmission electron diffraction patterns in the scanning electron microscope, SEM, using components of commercially available electron backscattered diffraction equipment, EBSD, normally used in a reflection geometry, was first

Giant Secondary Grain Growth in Cu Films on Sapphire

August 1, 2013

Author(s)

David L. Miller, Mark W. Keller, Justin Shaw, Katherine P. Rice, Robert Keller, Kyle M. Diederichsen

Single crystal metal films on insulating substrates are attractive for microelectronics and other applications, but they are difficult to achieve on macroscopic length scales. The conventional approach to obtaining such films is epitaxial growth at high

What's in a 'NYM?

July 1, 2013

Author(s)

Robert R. Keller

The field of electron microscopy, by its very diverse nature, abounds with acronyms: AEM, EF-TEM, ESEM, FE-SEM, HREM, HRTEM, HVEM, SEM, STEM, TEM, and VP-SEM, to name some instruments alone. Add in the different forms of data that these instruments might

Transmission EBSD in the Scanning Electron Microscope

May 1, 2013

Author(s)

Roy H. Geiss, Katherine P. Rice, Robert R. Keller

A new method for obtaining Kikuchi diffraction patterns from thin specimens in transmission has been developed for use in the SEM, scanning electron microscope, using a conventional electron backscatter diffraction (EBSD) detector and with a slight