Microscopy

Advancement in energy, environment and biology research relies heavily on micro-, nano- and atomic-scale chemical and structural imaging. Many microscopy instruments have high-resolution imaging capabilities including complementary chemical, structural and phase information, in-situ imaging in native environments and imaging of dynamic processes with high temporal-resolution.

Resources and Techniques

  • Nanoscale and sub-nanoscale imaging allows users to elucidate chemical processes and acquire structural data for a variety of samples such as nanostructures and cell-surface proteins.
  • Tomography yields three-dimensional reconstruction of transmission electron microscopy images generated for biological samples as well as for soft materials and samples with 3D structural heterogeneity.
  • Environmental particle analysis offers knowledge about non-volatile atmospheric particle composition and hydration properties using high-pressure scanning electron microscopy equipped with energy-dispersive x-ray analysis capability.
  • Environmental mode imaging techniques enable sample preservation to eliminate extensive preparation procedures that can introduce artifacts and make possible live-cell imaging and in situ imaging in liquids or controlled gas environments with high resolution microscopy.
  • Dynamic imaging capability enables real-time studies of nanosecond-scale dynamic processes with unprecedented spatial resolution, such as protein-protein interactions, with contrast at the single-molecule level.

In 2014, EMSL anticipates debuting its Dynamic Transmission Electron Microscope (DTEM) for the broad scientific community. It will enable dynamic in suit observation of cellular systems and components at near-atomic spatial resolution and nanosecond time resolution.

Quiet Wing for Advanced Microscopy
Seven microscopes are housed in the Quiet Wing, a space specially designed to reduce external factors, such as vibrations and electromagnetic fields, that can impede capture of high-resolution images. Read more about the Quiet Wing and its instrumentation.

Additonal Information:

Description

Capability Details

• Electron microscopes with tomography, cryo, scanning, photoemission and high-resolution (sub-nanometer) imaging capabilities
• Focused ion beam/scanning electron microscopes for specialized sample preparation and three-dimensional topographic and chemical imaging
• Nuclear magnetic resonance microscopy with 10-40-_m resolution to study the anatomy, metabolism and transport processes of live cell cultures, biofilms and tissue samples
• Dual Raman confocal microscope for analysis of radiological samples
• Single-molecule fluorescence tools to study molecular interactions in real time
• Scanning probe microscopy with capabilities ranging from examination of dynamic nanoscale processes in condensed environments to high resolution studies of catalysis materials in ultra-high vacuum.

 

Instruments

EMSL's ultra-high vacuum, low-temperature scanning probe microscope instrument, or UHV LT SPM, is the preeminent system dedicated to surface...
Custodian(s): Igor Lyubinetsky
Type of Instrument:
Microscope
EMSL's ultra-high vacuum, variable-temperature scanning probe microscope system, or UHV VT SPM, is a state-of-the-art surface science tool...
Custodian(s): Igor Lyubinetsky
The LEAP® 4000 XHR local electrode atom probe tomography instrument enabled the first-ever comprehensive and accurate 3-D chemical imaging studies...
Custodian(s): Arun Devaraj, Daniel Perea
This FEI Tecnai T-12 cryo-transmission electron microscope (TEM) complements EMSL's broader microscopy suite and JEOL 2010 analytical high-...
Custodian(s): Alice Dohnalkova
The environmental scanning electron microscope (ESEM) is a new-generation SEM that can image samples under controlled environments and temperatures...
Custodian(s): Alexander Laskin, Scott Lea

Publications

The scalable synthesis of subnanometer metal clusters containing an exact number of atoms is of interest due to the highly size-dependent catalytic,...
The stability of sub-nanometer size gold clusters ligated with organic molecules is of paramount importance to the scalable synthesis of monodisperse...
The oxygen reduction/evolution reaction (ORR/OER) mechanisms in nonaqueous Li-O2 batteries have been investigated by using electron paramagnetic...
Electrochemical performance of the existing state-of-the art capacitors is not very high, key scientific barrier is that its charge storage mechanism...
The metallic compound MnBi is a promising rare-earth-free permanent magnet material. Compare to other rare-earth-free candidates, MnBi stands out for...

Science Highlights

Posted: November 20, 2014
Aluminum oxide, or alumina, has numerous industrial uses, including as a catalyst and a catalytic support. Characterizing alumina has been difficult...
Posted: October 07, 2014
The Science Steam reforming is a method for converting biomass-derived light hydrocarbons and aromatics into a mixture of carbon monoxide and...
Posted: September 22, 2014
Phototrophs are organisms that use sunlight to convert inorganic materials to organic materials. Researchers are studying these organisms’...
Posted: September 15, 2014
Knowing the distribution of atoms on the surfaces of electrodes or other materials could benefit the development of longer lasting batteries and...
Posted: September 08, 2014
The Science The formation of ice crystals in the atmosphere strongly affects cloud dynamics, cloud radiative properties and the water vapor budget,...

Advancement in energy, environment and biology research relies heavily on micro-, nano- and atomic-scale chemical and structural imaging. Many microscopy instruments have high-resolution imaging capabilities including complementary chemical, structural and phase information, in-situ imaging in native environments and imaging of dynamic processes with high temporal-resolution.

Resources and Techniques

  • Nanoscale and sub-nanoscale imaging allows users to elucidate chemical processes and acquire structural data for a variety of samples such as nanostructures and cell-surface proteins.
  • Tomography yields three-dimensional reconstruction of transmission electron microscopy images generated for biological samples as well as for soft materials and samples with 3D structural heterogeneity.
  • Environmental particle analysis offers knowledge about non-volatile atmospheric particle composition and hydration properties using high-pressure scanning electron microscopy equipped with energy-dispersive x-ray analysis capability.
  • Environmental mode imaging techniques enable sample preservation to eliminate extensive preparation procedures that can introduce artifacts and make possible live-cell imaging and in situ imaging in liquids or controlled gas environments with high resolution microscopy.
  • Dynamic imaging capability enables real-time studies of nanosecond-scale dynamic processes with unprecedented spatial resolution, such as protein-protein interactions, with contrast at the single-molecule level.

In 2014, EMSL anticipates debuting its Dynamic Transmission Electron Microscope (DTEM) for the broad scientific community. It will enable dynamic in suit observation of cellular systems and components at near-atomic spatial resolution and nanosecond time resolution.

Quiet Wing for Advanced Microscopy
Seven microscopes are housed in the Quiet Wing, a space specially designed to reduce external factors, such as vibrations and electromagnetic fields, that can impede capture of high-resolution images. Read more about the Quiet Wing and its instrumentation.

Additonal Information:

Investigating the Synthesis of Ligated Metal Clusters in Solution Using a Flow Reactor and Electrospray Ionization Mass

Abstract: 

The scalable synthesis of subnanometer metal clusters containing an exact number of atoms is of interest due to the highly size-dependent catalytic, electronic and optical properties of these species. While significant research has been conducted on the batch preparation of clusters through reduction synthesis in solution, the processes of metal complex reduction as well as cluster nucleation, growth and post-reduction etching are still not well understood. Herein, we demonstrate a temperature-controlled flow reactor for studying cluster formation in solution at well-defined conditions. Employing this technique methanol solutions of a chloro(triphenylphosphine)gold precursor, 1,4-bis(diphenylphosphino)butane capping ligand and borane-tert-butylamine reducing agent were combined in a mixing tee and introduced into a heated capillary with an adjustable length. In this manner, the temperature dependence of the relative abundance of different ionic reactants, intermediates and products synthesized in real time was characterized using online mass spectrometry. A wide distribution of doubly and triply charged cationic gold clusters was observed as well as smaller singly charged metal-ligand complexes. The results demonstrate that temperature plays a crucial role in determining the relative population of cationic gold clusters and, in general, that higher temperature promotes the formation of doubly charged clusters and singly charged metal-ligand complexes while hindering the growth of triply charged clusters. Moreover, the distribution of clusters observed at elevated temperatures is found to be consistent with that obtained at longer reaction times at room temperature, thereby demonstrating that heating may be used to access cluster distributions characteristic of different stages of reduction synthesis in solution.

Citation: 
Olivares AM, J Laskin, and GE Johnson.2014."Investigating the Synthesis of Ligated Metal Clusters in Solution Using a Flow Reactor and Electrospray Ionization Mass Spectrometry."Journal of Physical Chemistry A 118(37):8464-8470. doi:10.1021/jp501809r
Authors: 
AM Olivares
J Laskin
GE Johnson
Facility: 
Volume: 
118
Issue: 
37
Pages: 
8464-8470
Publication year: 
2014

Size-dependent stability toward dissociation and ligand binding energies of phosphine-ligated gold cluster ions.

Abstract: 

The stability of sub-nanometer size gold clusters ligated with organic molecules is of paramount importance to the scalable synthesis of monodisperse size-selected metal clusters with highly tunable chemical and physical properties. For the first time, a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR-MS) equipped with surface induced dissociation (SID) has been employed to investigate the time and collision energy resolved fragmentation behavior of cationic doubly charged gold clusters containing 7-9 gold atoms and 6-7 triphenylphosphine (TPP) ligands prepared by reduction synthesis in solution. The TPP ligated gold clusters are demonstrated to fragment through three primary dissociation pathways: (1) Loss of a neutral TPP ligand from the precursor gold cluster, (2) asymmetric fission and (3) symmetric fission and charge separation of the gold core resulting in formation of complementary pairs of singly charged fragment ions. Threshold energies and activation entropies of these fragmentation pathways have been determined employing Rice-Ramsperger-Kassel-Marcus (RRKM) modeling of the experimental SID data. It is demonstrated that the doubly charged cluster ion containing eight gold atoms and six TPP ligands, (8,6)2+, exhibits exceptional stability compared to the other cationic gold clusters examined in this study due to its large ligand binding energy of 1.76 eV. Our findings demonstrate the dramatic effect of the size and extent of ligation on the gas-phase stability and preferred fragmentation pathways of small TPP-ligated gold clusters.

Citation: 
Johnson GE, TA Priest, and J Laskin.2014."Size-dependent stability toward dissociation and ligand binding energies of phosphine-ligated gold cluster ions."Chemical Science 5:3275-3286. doi:10.1039/c4sc00849a
Authors: 
GE Johnson
TA Priest
J Laskin
Facility: 
Volume: 
0
Issue: 
0
Pages: 
0
Publication year: 
2014

The Mechanisms of Oxygen Reduction and Evolution Reactions in Nonaqueous Lithium-Oxygen Batteries.

Abstract: 

The oxygen reduction/evolution reaction (ORR/OER) mechanisms in nonaqueous Li-O2 batteries have been investigated by using electron paramagnetic resonance spectroscopy in this work. We identified the superoxide radical anion (O2•-) as an intermediate in the ORR process using 5,5-dimethyl-pyrroline N-oxide as a spin trap, while no O2•- in OER was detected during the charge process. These findings provide insightful understanding on the fundamental oxygen reaction mechanisms in rechargeable nonaqueous Li-O2 batteries.

Citation: 
Cao R, ED Walter, W Xu, EN Nasybulin, P Bhattacharya, ME Bowden, MH Engelhard, and J Zhang.2014."The Mechanisms of Oxygen Reduction and Evolution Reactions in Nonaqueous Lithium-Oxygen Batteries."ChemSusChem 7(9):2436-2440. doi:10.1002/cssc.201402315
Authors: 
R Cao
ED Walter
W Xu
EN Nasybulin
P Bhattacharya
ME Bowden
MH Engelhard
J Zhang
Instruments: 
Volume: 
7
Issue: 
9
Pages: 
2436-2440
Publication year: 
2014

Effect of Composition and Heat Treatment on MnBi Magnetic Materials.

Abstract: 

The metallic compound MnBi is a promising rare-earth-free permanent magnet material. Compare to other rare-earth-free candidates, MnBi stands out for its high intrinsic coercivity (Hci) and its large positive temperature coefficient. Several groups have demonstrated that the Hci of MnBi compound in thin film or in powder form can exceed 12 kOe and 26 kOe at 300 K and 523 K, respectively. Such steep increase in Hci with increasing temperature is unique to MnBi. Consequently, MnBi is a highly sought-after hard phase for exchange coupling nanocomposite magnets. The reaction between Mn and Bi is peritectic, so Mn tends to precipitate out of the MnBi liquid during the solidification process. As result, the composition of the Mn-Bi alloy with the largest amount of the desired LTP (low temperature phase) MnBi and highest saturation magnetization will be over-stoichiometric and rich in Mn. The amount of additional Mn required to compensate the Mn precipitation depends on solidification rate: the faster the quench speed, the less Mn precipitates. Here we report a systematic study of the effect of composition and heat treatments on the phase contents and magnetic properties of Mn-Bi alloys. In this study, Mn-Bi alloys with 14 compositions were prepared using conventional metallurgical methods such as arc melting and vacuum heat treatment, and the obtained alloys were analyzed for compositions, crystal structures, phase content, and magnetic properties. The results show that the composition with 55 at.% Mn exhibits the highest LTP MnBi content and the highest magnetization. The sample with this composition shows >90 wt.% LTP MnBi content. Its measured saturation magnetization is 68 emu/g with 2.3 T applied field at 300 K; its coercivity is 13 kOe and its energy product is 12 MGOe at 300 K. A bulk magnet fabricated using this powder exhibits an energy product of 8.2 MGOe.

Citation: 
Cui J, JP Choi, E Polikarpov, ME Bowden, W Xie, G Li, Z Nie, N Zarkevich, MJ Kramer, and DD Johnson.2014."Effect of Composition and Heat Treatment on MnBi Magnetic Materials."Acta Materialia 79:374-381. doi:10.1016/j.actamat.2014.07.034
Authors: 
J Cui
JP Choi
E Polikarpov
ME Bowden
W Xie
G Li
Z Nie
N Zarkevich
MJ Kramer
DD Johnson
Volume: 
Issue: 
Pages: 
Publication year: 
2014

In Situ One-Step Synthesis of Hierarchical Nitrogen-Doped Porous Carbon for High Performance Supercapacitors.

Abstract: 

Electrochemical performance of the existing state-of-the art capacitors is not very high, key scientific barrier is that its charge storage mechanism wholly depends on adsorption of electrolyte on electrode. We present a novel method for the synthesis of nitrogen -doped porous carbons and address the drawback by precisely controlling composition and surface area. Nitrogen-doped porous carbon was synthesized using a self-sacrificial template technique without any additional nitrogen and carbon sources. They exhibited exceptionally high capacitance (239 Fg-1) due to additional pseudocapacitance originating from doped nitrogen. Cycling tests showed no obvious capacitance decay even after 10,000 cycles, which meets the requirement of commercial supercapacitors. Our method is simple and highly efficient for the production of large quantities of nitrogen-doped porous carbons.

Citation: 
Jeon JW, R Sharma, P Meduri, BW Arey, HT Schaef, J Lutkenhaus, JP Lemmon, PK Thallapally, MI Nandasiri, BP McGrail, and SK Nune.2014."In Situ One-Step Synthesis of Hierarchical Nitrogen-Doped Porous Carbon for High Performance Supercapacitors."ACS Applied Materials & Interfaces 6(10):7214-7222. doi:10.1021/am500339x
Authors: 
JW Jeon
R Sharma
P Meduri
BW Arey
HT Schaef
J Lutkenhaus
JP Lemmon
PK Thallapally
MI Nasiri
BP McGrail
SK Nune
Instruments: 
Volume: 
6
Issue: 
10
Pages: 
7214-7222
Publication year: 
2014

Microstructural Response of Variably Hydrated Ca-Rich Montmorillonite to Supercritical CO2.

Abstract: 

We report on ab initio molecular dynamics simulations of Ca-rich montmorillonite systems, in different hydration states in the presence of supercritical CO2. Analysis of the molecular trajectories provides estimates of the relative H2O:CO2 ratio per interspatial cation. The vibrational density of states in direct comparison with dipole moment derived IR spectra for these systems provide unique signatures that can used to follow molecular transformation. In a co-sequestration scenario, these signatures could be used to identify the chemical state and fate of Sulfur compounds. Interpretation of CO2 asymmetric stretch shift is given based on a detailed analysis of scCO2 structure and intermolecular interactions of the intercalated species. Based on our simulations, smectites with higher charge interlayer cations at sub-single to single hydration states should be more efficient in capturing CO2, while maintaining caprock integrity. This research would not have been possible without the support of the office of Fossil Energy, Department of Energy. The computational resources were made available through a user proposal of the EMSL User facility, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.

Citation: 
Lee MS, BP McGrail, and VA Glezakou.2014."Microstructural Response of Variably Hydrated Ca-Rich Montmorillonite to Supercritical CO2."Environmental Science & Technology 48(15):8612-8619. doi:10.1021/es5005889
Authors: 
MS Lee
BP McGrail
VA Glezakou
Instruments: 
Volume: 
48
Issue: 
15
Pages: 
8612-8619
Publication year: 
2014

Oxidative Remobilization of Technetium Sequestered by Sulfide-Transformed Nano Zerovalent Iron.

Abstract: 

The dissolution of Tc(IV) sulfide and concurrent transformation of sulfidated ZVI during 2 oxidation were examined. Kinetic data obtained with 10 mL batch reactors showed that Tc(VII) 3 reduced by sulfidated nZVI has significantly slower reoxidation rates than Tc(VII) reduced by 4 nZVI only. In a 50 mL batch reactor, initial inhibition of Tc(IV) dissolution was apparent and 5 lasted until 120 hours at S/Fe = 0.112, presumably due to the redox buffer capacity of FeS. This 6 is evidenced by the parallel trends in oxidation-reduction potentials (ORP) and Tc dissolution 7 kinetics. Mӧssbauer spectra and micro X-ray diffraction of S/Fe = 0.112 suggested the 8 persistence of FeS after 24-h oxidation although X-ray photoelectron spectroscopy indicated 9 substantial surface oxidation. After 120-h oxidation, all characterizations showed complete 10 oxidation of FeS, which further indicates that FeS inhibits Tc oxidation. X-ray absorption 11 spectroscopy for S/Fe = 0.011 showed significantly increasing percentage of TcS2 in the solid 12 phase after 24-h oxidation, indicating TcS2 is more resistant to oxidation than TcO2. At S/Fe = 13 0.112, the XAS results revealed significant transformation of Tc speciation from TcS2 to TcO2 14 after 120-h oxidation at S/Fe = 0.112. Given that no apparent Tc dissolution occurred during this 15 period, the speciation transformation might play a secondary role in hindering Tc oxidation, 16 especially as redox buffer capacity approached depletion.

Citation: 
Fan D, R Anitori, BM Tebo, PG Tratnyek, JS Lezama Pacheco, RK Kukkadapu, L Kovarik, MH Engelhard, and ME Bowden.2014."Oxidative Remobilization of Technetium Sequestered by Sulfide-Transformed Nano Zerovalent Iron."Environmental Science & Technology 48(13):7409-7417. doi:10.1021/es501607s
Authors: 
D Fan
R Anitori
BM Tebo
PG Tratnyek
JS Lezama Pacheco
RK Kukkadapu
L Kovarik
MH Engelhard
ME Bowden
Instruments: 
Volume: 
48
Issue: 
13
Pages: 
7409-7417
Publication year: 
2014

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