Nanoscience – Novel spectroscopy by using aberrations

It was recently proposed that electron magnetic circular dichroism can be measured in scanning transmission electron microscopy with atomic resolution by tuning the phase distribution of an electron beam. Here, we describe the theoretical and practical aspects for the detection of out-of-plane and in-plane magnetization utilizing atomic size electron probes. We present the calculated optimized astigmatic probes and discuss how to achieve them experimentally.

When life gives you lemons, make lemonade. At Oak Ridge National Laboratory and Uppsala University, researchers have done the scientific equivalent by using, rather than eliminating, flaws inherent to electron microscopy to create probes for performing novel atomic-level spectroscopy.

The theory and practical aspects of their “aberrated probes” are described in a recent article in the journal Physical Review B. “Here, we focus on how one can detect magnetic properties in materials,” said Juan Carlos Idrobo of the Center for Nanophase Materials Sciences, a Department of Energy User Facility at ORNL.

“However, electron probe shapes can be tailored via specific aberrations to detect other material properties with unprecedented spatial resolution, such as charge ordering, crystal field splitting, spin-orbit coupling, optical dichroism and other physical phenomena associated with broken symmetries.”

Reference:

Aberrated electron probes for magnetic spectroscopy with atomic resolution: Theory and practical aspects by Jan Rusz, Jaun arlos Idrobo

Phys. Rev. B 93, 104420 – Published 24 March 2016

DOI: http://dx.doi.org/10.1103/PhysRevB.93.104420

Oak Ridge National Laboratory

#Spectroscopy