A team of researchers has used a new Scanning Transmission Electron Microscope (STEM) technique to image the electron distribution in ionic compounds known as electrides — especially the electrons that float loosely within pockets and appear separate from the atomic network.
The new technique, Differential Phase Contrast (DPC) in STEM, measures and maps electric fields and charge distributions inside a material. The study is the first time that DPC has been used in this way. By analyzing charge images of dozens of such channels, the team found that only some contain the negative charge predicted by theoretical calculations, while others have significantly less negative or even a small concentration of positive charge.
Currently, computer scientists are deploying machine-learning techniques to quickly identify materials with electride signatures so they can be further investigated. It is already known that electrides are good for storing hydrogen, can be used as catalysts, carry strong currents because of their high electron mobility, and often exhibit unconventional magnetism, even superconductivity. These and other properties make their development attractive for an array of emerging technologies.