A comparison of XEDS and EELS with the use of conventional beryllium window and windowless Si(Li) detectors

The use of electron energy loss spectroscopy (EELS) for light-element identification is now a well-established technique. Although not a new concept, modified Si(Li) detectors with the conventional beryllium window replaced by a ultra-thin aluminum-coated parylene window (UTW), or with the beryllium completely removed for windowless (WL) operation, have now become routinely available. Since both systems can now be easily interfaced to modern analytical electron microscopes (AEMs) it becomes relevant to determine experimentally the relative merits of the two different techniques for light-element identification and subsequent quantification in both simple systems and complex materials problems, such as precipitate identification in multicomponent alloys. In this preliminary study, the authors have systematically studied the relationship between EELS and XEDS (using a WL detector) for elements ranging from lithium through gallium, with the exception of neon and argon, as well as typical problems in precipitate analysis in thermally aged 316 stainless steel specimens