The Quantum Spin-Polarized Low-Energy Electron Microscope (QSPLEEM) is an Elmitec LEEM III microscope. It is a unique, highly-modifiable low-voltage electron microscope for the study of surfaces and interfaces with a liquid helium sample stage cryostat designed to reach temperatures of ~4 K. The instrument is very sensitive to structural and electronic properties of sample surfaces and is well-suited for in-situ research within a highly controlled sample environment with the ability to vary sample temperature and apply fields and biases. Spin-polarization of the electron beam permits imaging of magnetic domain microstructure.
This instrument is designed to be easily adaptable to enable various types of experiments and exploration of new ideas. During imaging, it is usually possible to provide the following: clean vacuum (low 10-11 torr); variable sample temperature (~ 4 K to over 2500 K); in-situ deposition of films or multilayers (most metals, some oxides), co-deposition of several components. Within limits, magnetic fields at the sample can be adjusted. Samples can be introduced through a loadlock and can be cleaned within the same UHV system (low-energy sputtering with noble- or reactive gases, heating, in-situ cleaving…). Available imaging/spectroscopic modes include bright/dark field low-energy electron microscopy, low-energy electron diffraction, photoemission electron microscopy, angle-resolved reflection electron spectroscopy, and Auger electron spectroscopy.
Available imaging and spectroscopic modes include:
- Spin-polarized low-energy electron microscopy (SPLEEM)
- Bright/Dark field low-energy electron microscopy (LEEM)
- Low-energy electron diffraction (LEED)
- Work function mapping
- Photoemission electron microscopy (PEEM)
- Thermionic electron emission mapping
- Angle-resolved reflection electron spectroscopy (ARRES)
Specifications
- Electron energy: typically 0 to 200 eV, with an energy width of ~0.1 eV
- Spin-polarization: normally ~30%, adjustable to point in any polar/azimuthal direction
- Spatial resolution: ~15 nm laterally, with atomic resolution along the surface normal
- Angular resolution of magnetization direction: better than 2 degrees
- Time resolution: frame rate up to 20 fps, with an exposure time of several milliseconds per frame required for reasonable signal quality
