EELS/EDS measures the elemental content of atomic-scale and nano-scale structures. EELS is best for low atomic number (Z) elements (eg Be, B, C, N, O, F, Na, Mg). EDS is best for atomic number elements (Al – Zr).
Electron energy loss spectroscopy (EELS) as a STEM measurement technique made possible with the addition of an electron spectrometer. The high-energy convergent electron beam in STEM provides local information of the sample, even down to atomic dimensions. With the addition of EELS, elemental identification is possible and even additional capabilities of determining electronic structure or chemical bonding of atomic columns.
With the GIF Quantum®, there is no compromise between EFTEM and EELS performance. Gatan’s patented sensor readout architecture allows the same CCD sensor to be used interchangeably as a full-frame high-quality imaging device, a high-speed live viewing device, and an ultra fast spectroscopy device. Aberration correction up to 5th order allows the use of a 1.8x larger 9 mm entrance aperture for EFTEM and a 2x larger 5 mm entrance aperture for energy loss spectroscopy.
Grey: Cu L2,3-edges; Red: O K-edge; Blue: Co L2,3-edges; Green: Ti L2,3-edges; Light Blue: N K-edge. A 520 x 520 EELS spectrum image (2 GB data-set).