# Presentation: 519484

## BASIC ENERGY SCIENCES -- Serving the Present, Shaping the Future

***BASIC ENERGY SCIENCES -- Serving the Present, Shaping the Future***

**Transmission Electron Aberration-free Microscope (TEAM) Project Update**

**Altaf H. Carim**
**Division of Materials Sciences and Engineering**
**Office of Basic Energy Sciences**
**U.S. Department of Energy**

***Basic Energy Sciences Advisory Committee meeting***
***July 23, 2002***

## Energetic electrons as a probe of matter

-   strong (Coulombic) interactions (with both electrons and nuclei)
-   very short wavelengths (~ 2.5 pm at 200 kV)
-   high source brightness (~ 1032 s-1 m-2 ster-1)
-   readily focused (can form images; probes ≤ 0.1 nm for scanning)
-   exceptional spatial resolution (can exceed 0.1 nm for imaging)

## High-energy electron scattering: TEM, STEM

- Controlled environment TEM at University of Illinois at Urbana-Champaign (courtesy FS-MRL, UIUC)

- Ray diagrams illustrating reciprocity (courtesy J. Silcox)

## Collaborative effort from four DOE-BES centers

**Advanced Light Source**

**Stanford Synchrotron Radiation Lab**

**National Synchrotron Light Source**

**Advanced Photon Source**

**National Center for Electron Microscopy**

**Shared Research Equipment Program**

**Center for Microanalysis of Materials**

**Electron Microscopy Center for Materials Research**

**High-Flux Isotope Reactor**

**Intense Pulsed Neutron Source**

**Combustion Research Facility**

**James R. MacDonald Lab**

**Pulse Radiolysis Facility**

**Materials Preparation Center**

**Los Alamos Neutron Science Center**

**Center for Nanophase Materials Sciences**

**Spallation Neutron Source**

**Linac Coherent Light Source**

**Center for Integrated Nanotechnologies**

**Molecular**
**Foundry **

**Newest NSRCs ****at ANL and BNL **

## What is the TEAM project?

- A collaborative development project to design, build, and operate next-generation electron microscopes
- Capitalize on several recent major developments, including the correction of limiting lens aberrations
- Definition of a common base instrument platform, with a modular approach to tailoring instruments for specific purposes
- Focus on enabling new, fundamental science via
-   quantitative in-situ microscopy
-   synchrotron spectral resolution at atomic spatial resolution
-   sub-Ångstrom resolution in real time and 3-D

## Modular experimental stations for in-situ work

## Modular sample holder configurations

## Spherical and Chromatic Aberration

- rmin  ≈  0.6  λ3/4  Cs1/4
- rmin is resolution limit

- rchr  ≈  Cc  (ΔE / E0)  β
- rchr is disk of confusion from chromatic aberration

## Benefits of Aberration Correction

- d  Å

- PCTF

- Cs-Cc-corrected

- Cs-corrected

- + Monochromator

- Lorenzlens

- A lens design at 200 kV intended for magnetic imaging (Lorentz microscopy) maintaining a large, field-free volume at the sample (courtesy B. Kabius)

- Spherical aberration correction provides much higher current at a given probe size for quantitative STEM (courtesy J. Spence)

- contrast

## More Benefits of Aberration Correction

- Improvement in spherical aberration provides much improved signal in smaller probe sizes (courtesy J. Silcox)

- Reducing chromatic aberration enhances resolution and contrast for imaging with electrons undergoing energy losses, allowing chemically-specific images at atomic resolution (courtesy B. Kabius)

**Example : Si-K edge, 1.8 keV**
- E = 50 eV,
- HT : 200 kV, gap = 25 mm

## How are aberrations corrected?

## Impact of Aberration Correction on Microscopy

**Current**

- (Courtesy J. Silcox, after** Harald Rose)**

- STEM (120 keV) {Batson et al.}

## TEAM aims to enable new fundamental science

- Some examples:
- Nanoscale tomography, including 3-dimensional determination of glass structure and possibly location of individual point defects
- Direct observation of atomic level microstructure during controlled, quantifiable deformation
- In-situ control of electric and magnetic fields for direct observations of interfacial structure, segregation, and defects in active devices and changes induced by fields
- Single-column microanalysis, including chemical state information available by improved energy resolution

## Recent breakthroughs and opportunities

- (courtesy J. Spence)

## Recent breakthroughs and opportunities

- (courtesy J. Spence)

## Recent breakthroughs and opportunities

***Recent breakthroughs and opportunities***

- (courtesy J. Spence)

## Recent breakthroughs and opportunities

- (courtesy F. Ross)

## Recent breakthroughs and opportunities

- (courtesy F. Ross)

## Recent breakthroughs and opportunities

- (courtesy F. Ross)

## Status of TEAM project

- Preliminary “vision document” was supplied for BESAC subpanel’s 2000 report; the subpanel recommended favorable consideration of such an effort
- Second workshop last week at Berkeley drew attendance of over 100 and very strong interest in, and expressions of support for, the program
- Scientific advisory board established to provide guidance
- Full proposal involving at least the four electron beam microcharacterization centers, with possible participation from other parties, is expected by the end of the year.
- Rough estimates of cost are in the neighborhood of $70M over five years.