Variable Temperature Electron Energy-Loss Spectroscopy

Abstract

Atomic column-resolved electron energy-loss spectroscopy (EELS) in combination with Z-contrast imaging in a scanning transmission electron microscope (STEM) has become a very popular approach for characterizing the atomic and electronic structures of interfaces and defects in a wide range of solid-state materials. However, while the development of aberration correction in electron microscopes now allows for sub-A spatial resolution to be achieved, many of these high-resolution experiments are currently limited to the ambient environment inside the microscope column. Yet, there is an increased interest in the areas of catalyst and functional oxide research to utilize in situ heating and cooling experiments with high spatial resolution. In this chapter, we will describe recent advances in atomic-resolution variable temperature EELS and discuss the required setup and techniques for achieving high-resolution variable temperature Z-contrast imaging and EELS. In particular, we will concentrate on three examples where in situ heating and cooling experiments in the temperature range between 10 and 700 K have been crucial to understanding the magnetic and electronic transport properties of functional oxide materials. We will also discuss some of the limitation of current heating/cooling sample holder technologies for high-resolution Z-contrast imaging and EELS.