Aberration-corrected Lorentz Transmission Electron Microscope (ALTEM)

National Laboratory: 
Argonne National Laboratory
Characterization Class: 
Microscopy
Description: 

The ALTEM instrument is dedicated to imaging magnetic fields and magnetic materials in a field-free region, which is critical for magnetic materials. Compared to standard magnetic imaging, aberration correction allows for enhanced spatial resolution.

Capability Bounds: 

The sample must be in the form of a thinned TEM sample, which can be thinned from bulk using standard techniques. Samples can be up to 3 mm diameter disks for static imaging and up to 2 mm diameter for magnetization reversal studies (in-plane applied magnetic field up to +/- 800 Gauss).

Unique Aspects: 

Unique, dedicated aberration-corrected LTEM with high spatial resolution for imaging magnetic domain structure with up to 2 nm spatial resolution and microstructure with up to 0.4 nm spatial resolution in a field-free region. In addition to magnetizing, the ALTEM's capabilities include tomography, heating and cooling stages, and an electron biprism.

Availability: 

The instrument is used by a single group at ANL and does not reside in a user facility.

Single Point of Contact: 

Dr. Amanda Petford-Long, petford.long@anl.gov, 630-252-5481

References: 
  1. 'In-situ Lorentz TEM magnetization studies of a Ni-Mn-Ga ferromagnetic shape memory alloy,' A. Budruk, C. Phatak, A.K. Petford-Long, M. De Graef, Acta Mat. 59, 4895_4906 (2011).
  2. 'In-situ Lorentz TEM magnetization studies on a Fe-Pd-Co martensitic alloy,' A. Budruk, C. Phatak, A.K. Petford-Long, M. De Graef, Acta Mat. 59, 6646_6657 (2011).
  3. 'Ferromagnetic domain behavior and phase transition in bilayer manganites investigated at the nanoscale,' C. Phatak, A.K. Petford-Long, H. Zheng, J.F. Mitchell, S. Rosenkranz, M. Norman, Phys. Rev B 92, 224418 (2015). DOI: 10.1103/PhysRevB.92.224418.
  4. 'Nanoscale skyrmions in a non-chiral metallic multiferroic: Ni2MnGa,' C. Phatak, O. Heinonen, M. De Graef, A. Petford-Long, Nano Lett. (2016) DOI: 10.1021/acs.nanolett.6b01011.
Supporting Document(s): 

This capability is a user facility managed by the U.S. Department of Energy's Office of Science. Each user facility has established processes for submitting a proposal and gaining access. Visit http://science.energy.gov/user-facilities/user-resources/getting-started for more information.