Metastable De-excitation Spectroscopy (MDS) is a surface analysis technique with perfect surface sensitivity. A metastable atom will de-excite ~5Å from a surface and give rise to an ejected electron energy spectrum that is unique to the surface electronic, chemical, and magnetic properties. There is no contribution to the signal from the bulk of the sample unlike in other surface analysis techniques such as UPS, XPS, EELS, and AES. This property of MDS makes it ideal for studying samples where surface information is required, such as semiconductors, organic thin films, biomaterials, and magnetic films.
We are constructing an instrument that overcomes the limitations of conventional metastable atom sources by using laser cooling techniques to first collimate, and then focus, a metastable helium (He*) beam. Once completed we will have a high-purity ultra-high intensity He* beam with which to perform surface analysis using MDS. Ultimately the electrons ejected from the surface in the de-excitation process will be imaged to develop the technique into a microscopy. This will be used to explore a variety of materials:
For more information on our experimental work click here.
