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VERSION:2.0
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METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20260418T140320Z
UID:https://www.mpie.de/events/45182/3755656
DTSTART:20260409T113000Z
DTEND:20260409T123000Z
CLASS:PUBLIC
CREATED:20260320T130217Z
DESCRIPTION:Recent advances in transmission electron microscopy (TEM) have 
 pushed spatial resolution into the 0.5 Å regime\, shifting imaging from
  an instrument-limited to an object-limited discipline and enabling the di
 rect visualization of individual atoms and molecules. However\, the struct
 ures and dynamics of many functional materials\, particularly catalysts\, 
 are strongly influenced by their local environment\, creating challenges f
 or imaging under conventional high‑vacuum and high‑dose conditions. In
  this seminar\, two complementary developments in instrumentation and imag
 ing methodology will be presented\, each expanding the capabilities of TEM
  for both in‑situ and ex‑situ studies. First\, open‑cell TEM\, also 
 known as environmental TEM (ETEM)\, will be described. The VISION PRIME pl
 atform\, built on an ultra-stable SPECTRA ETEM system\, will be introduced
 . Through the integration of a 5th-order aberration corrector\, monochroma
 ted illumination\, differential pumping that enables operation at 10-20 
 mbar gas pressure\, and direct electron detection\, a 0.5 Å information
  limit is maintained even in gas atmospheres. Using Young’s fringes and 
 exit wave phase reconstruction\, atomic‑resolution visualization of gas
 –surface interactions on a Au nanoparticle at 1 mbar N₂ has been dem
 onstrated\, revealing gas-dependent variations in atomic column widths and
  enabling operando studies of catalytic processes. Second\, examples of ex
 it wave phase reconstruction obtained using a low dose focal series recons
 truction (LD‑FSR) methodology will be presented. This approach enables 1
 .6 Å‑resolution imaging of organic materials with limited radiation d
 amage to the sample. By rapidly recording hundreds of low dose frames at c
 ryogenic temperatures and reconstructing the exit plane wavefunction\, abe
 rration-corrected phase images up to the microscope’s information limit 
 are obtained. In this way\, access is provided to organic crystal structur
 es and aperiodic features that would otherwise be obscured under strong de
 focus conditions and low signal-to-noise ratio. When combined with complem
 entary methods such as density functional theory\, reliable determination 
 of molecular packing and local structural distortions is enabled directly 
 from real-space images. Finally\, a combined approach employing LD-FSR and
  4D-STEM for imaging sensitive organic crystalline polymers will be demons
 trated.\nSpeaker: Dr. Idan Biran 
LAST-MODIFIED:20260320T130711Z
LOCATION:Max Planck Institute for Sustainable Materials\, Room: BDS Seminar
  room
ORGANIZER;CN=on invitation of Dr. Siyuan Zhang / Prof. Christina Scheu:mail
 to:
SUMMARY:Advancing In-Situ and ex-Situ Transmission Electron Microscopy with
  Low Dose Focal Series Reconstruction and 4D‑STEM
URL;VALUE=URI:https://www.mpie.de/events/45182/3755656
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