Energy-drift correction of electron energy-loss spectra from prolonged data accumulation of low SNR signals.

The demand for analysis of trace elements in atomically localized areas by electron energy-loss spectroscopy (EELS) in transmission electron microscopy is increasing. Unfortunately, the prolonged data acquisitions required to achieve an acceptable signal-to-noise ratio (SNR) tend to deteriorate the energy resolution because of spectral drifts due to instrumental instability. We developed a macroscript for a Gatan Digital Micrograph(TM) to control an ENFINA 1000 EEL spectrometer that corrects for energy drifts during data accumulation. The script successfully achieved a core-loss spectrum for a sample having approximately 1 at% elemental concentration, and provided a sufficient SNR for chemical state analysis.