Publications

Displaying 1 - 20 of 20

Transmission Electron Imaging and Diffraction of Asbestos Fibers in a Scanning Electron Microscope

June 24, 2024

Author(s)

Jason Holm, Elisabeth Mansfield

Test protocols for airborne clearance of asbestos abatement sites define the collection, imaging and quantification of asbestos with transmission electron microscopy (TEM). Since those protocols were developed 35 years ago, scanning electron microscope

Detailed analysis of the synthesis and structure of MAX phase (Mo0.75V0.25)5AlC4 and its MXene (Mo0.75V0.25)5C4

June 27, 2023

Author(s)

Rose Snyder, Mikkel Juelsholt, Curran Kalha, Jason Holm, Elisabeth Mansfield, Tien-Lin Lee, Pardeep Thakur, Aysha Riaz, Benjamin Moss, Anna Regoutz, Christina Birkel

MAX phases with the general formula Mn+1AXn are layered carbides, nitrides and carbonitrides with varying stacking sequence of layers of M6X octahedra and the A-element depending on n. While "211" MAX phases (n = 1) are very common, MAX phases with higher

Additive manufacturing titanium powder oxygen variation within a single powder bed due to differences in powder size and oxygen content

January 31, 2023

Author(s)

Nicholas Derimow, Elisabeth Mansfield, Jason Holm, Nik Hrabe

Thermogravimetric analysis of Ti-6Al-4V powders (virgin Grade 5 and a once used Grade 23) was conducted up to 800 C in an industrial grade Ar environment. A standard starting particle size distribution (PSD) for electron beam powder-bed fusion (PBF-EB)

Low-keV Transmission Electron Imaging and Diffraction of Ultrathin Highly Beam-Sensitive MFI Zeolites in a Scanning Electron Microscope

December 20, 2022

Author(s)

Jason Holm

This manuscript demonstrates the susceptibility of ultrathin Mobil Five (MFI) zeolite nanosheets to low-keV electron beam damage in a scanning electron microscope (SEM). Beam dose rates and characteristic beam doses are quantified at beam energies from 15

X-Ray Computed Tomography using Partially Coherent Fresnel Diffraction with Application to an Optical Fiber

January 18, 2021

Author(s)

Zachary H. Levine, Edward Garboczi, Adele Peskin, Axel A. Ekman, Elisabeth Mansfield, Jason Holm

An algorithm for partially coherent x-ray computed tomography including Fresnel diffraction is developed and applied to an optical fiber. The computing time is a few times worse than the projective counterpart. A code using the algorithm is used to

Orientation Mapping of Graphene Using 4D STEM-in-SEM

October 13, 2020

Author(s)

Benjamin W. Caplins, Jason D. Holm, Ryan M. White, Robert R. Keller

A scanning diffraction technique is implemented in the scanning electron microscope. The technique, referred to as 4D STEM-in-SEM (four-dimensional scanning transmission electron microscopy in the scanning electron microscope), collects a diffraction

Introduction to STEM-in-SEM Part 1: Imaging and Diffraction with Common Commercially Available Transmission Detectors

March 12, 2020

Author(s)

Jason D. Holm, Benjamin W. Caplins

Introduction to STEM-in-SEM Part 2: Imaging and Diffraction with a Programmable Pixelated Detector

March 12, 2020

Author(s)

Jason D. Holm, Benjamin W. Caplins

Obtaining Diffraction Patterns from Annular Dark-Field STEM-in-SEM Images: Towards a Better Understanding of Image Contrast

February 24, 2020

Author(s)

Jason D. Holm, Benjamin W. Caplins, Jason P. Killgore

This contribution demonstrates experimentally how a series of annular dark-field transmission images collected in a scanning electron microscope (SEM) with a basic solid-state detector can be used to quantify electron scattering distributions (i,e

Exfoliated transition metal dichalcogenide (TMD) nanosheets for supercapacitor and sodium ion battery applications

August 14, 2019

Author(s)

Jonathan Turley, Santanu Mukherjee, Elisabeth Mansfield, Jason Holm, Lamuel David, Gurpreet Singh

The growing concerns regarding the safety, flammability and hazards posed by Li-ion systems has led to the research of alternative rechargeable metal-ion electrochemical storage technologies. Among the most notable of these are the Na-ion supercapacitors

A Workflow for Imaging 2D Materials using 4D STEM-in-SEM

August 4, 2019

Author(s)

Benjamin W. Caplins, Ryan M. White, Jason D. Holm, Robert R. Keller

A Programmable Transmission Electron Detector for Nanomaterials Characterization in a Scanning Electron Microscope

June 17, 2019

Author(s)

Jason D. Holm, Benjamin W. Caplins, Robert R. Keller

A new programmable detector for scanning transmission electron microscopy (pSTEM) is described. A digital micromirror array lies at the heart of the detector and serves as a programmable virtual objective aperture. Two sensors, a photomultiplier tube and a

Grain Orientation Mapping of Graphene in a Scanning Electron Microscope

May 1, 2019

Author(s)

Benjamin W. Caplins, Jason D. Holm, Robert R. Keller

A scanning transmission electron diffraction method is developed for use in the scanning electron microscope to perform orientational imaging microscopy of 2D materials. The method can generate grain orientational maps of monolayer graphene over a field of

A programmable dark-field detector for imaging two-dimensional materials in the scanning electron microscope

February 7, 2019

Author(s)

Benjamin W. Caplins, Jason D. Holm, Robert R. Keller

Unit cell orientation information is encoded in electron diffraction patterns of crystalline materials. Traditional transmission electron detectors implemented in the scanning electron microscope are highly symmetric and are insensitive to in-plane unit

Transmission Imaging with a Programmable Detector in a Scanning Electron Microscope

September 13, 2018

Author(s)

Benjamin W. Caplins, Jason D. Holm, Robert R. Keller

A new type of angularly selective electron detector for use in a scanning electron microscope is presented. The detector leverages a digital micromirror device (DMD) to take advantage of the benefits of two-dimensional (2D) imaging detectors and high

Using a Modular Aperture System to Obtain Annular Dark-Field Image Intensity Distributions as a Function of Scattering Angle.

June 15, 2018

Author(s)

Jason D. Holm

In this contribution, 10 nm-thick non-stoichiometric silicon nitride films were examined in a scanning electron microscope (SEM) using a zero-dimensional solid-state transmission electron detector equipped with a modular aperture system. Effects of several

Acceptance Angle Control for Improved Transmission Imaging in an SEM

March 1, 2017

Author(s)

Jason D. Holm, Robert R. Keller

This contribution presents a simple, cost-effective modular aperture system enabling comprehensive acceptance angle control for STEM-in-SEM imaging. The system is briefly described, and different ways to use it are explained. To demonstrate the utility of

Introducing a New NIST Reference Material: Multiwall Carbon Nanotube Soot

July 25, 2016

Author(s)

Ann C. Chiaramonti Debay, Ryan M. White, Jason D. Holm, Elisabeth Mansfield

Multi-walled carbon nanotubes (MWCNTs) play a significant role in the nascent nanotechnology industry, due to their remarkable combination of mechanical, thermal, and electrical properties. These materials are specialty additives, reinforcing a diverse

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

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

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