TEM Spectroscopies and Imaging in 2D/3D
Nanomagnetism in the TEM: Electron Magnetic Circular Dichroism (EMCD)
As devices and materials shrink to smaller sizes, the effects of interfaces play a larger role. In magnetic materials, the atoms at the surface of a particle or crystal behave differently than those within the bulk, often with effects not achievable in normal materials. How does this change arise? Could we harness these properties to fabricate new materials? How can one detect these changes reliably on the nanoscale? These are some of the questions we are exploring in Uppsala University’s Electron Microscopy and Nanoengineering group. One way to see the nanoscale structure of advanced magnetic materials is to use the Transmission Electron Microscope (TEM). This tool can be combined with a spectroscopy technique called Electron Magnetic Circular Dichroism (EMCD) to produce quantitative magnetic information with nanometer spatial resolution. This information is vital to the development of new magnetic materials ranging from magnetic recording media to spring-exchange magnets.
Responsibles: Klaus Leifer, Thomas Thersleff, Hasan Ali, and Sharath Kumar
3D Electron Tomography
My research interest is to investigate the novel materials properties (structural and chemical properties) using electron microscopy techniques, such as high resolution TEM, conventional TEM, STEM, spectroscopic imaging and 3D electron tomography associated techniques. It can be summarized as follows:
- Sample preparation for semiconductor materials
- Analysis of nanostructure and interface in the Si based solar cell thin films using electron energy loss spectroscopy (EELS), in particular plasmon excitations.
- 3D and multi-dimension electron tomography technique in nanometer resolution. Novel data processing methods on the gigantic spectra-image dataset.
- Newly developed 3D reconstruction methods, for example, conventional back projection reconstruction or Geometric reconstruction for electron tomography.
- Automatic electron tomography data acquisition, alignment methods in low dose mode for soft materials.
Responsibles: Klaus Leifer, Ling Xie
