Optimization of EDX performance in Tecnai TEMs.

The quality of X-ray spectra from FEGTEMs has been improved by three different means: the use of beryllium shields, improved collimation and improved specimen holder geometry. The improvements lead to a significant increase in peak-to-background ratios and a reduction in spurious peaks in the EDX spectra. A double-tilt, low-background specimen holder was designed to allow EDX analysis at 0 degrees of tilt without shadowing.