Recent development in EELS spectrometer technology

A,Maigne1, M.Rabara1

1Nippon Gatan 3F Sakurai bldg 2-8-19 Fukagawa, Koto-ku Tokyo 135-0033 Japan

Energy Electron Loss Spectroscopy has been proven many times to be the state of the art analysis method for material characterization. TEM and STEM performances have increased drastically with the development of Cs correctors as well as monochromators. Energy resolution and probe current has drastically increased, therefore we redesign from the ground up our spectrometers. Our new post-column filter, the GIF Quantum, combines advanced dodecapole-based electron optics with a fast CCD camera system to yield an imaging filter that defines the new state-of-the-art in the capture of both highly detailed EELS and EFTEM data sets with maximum throughput.

By combining a new high-speed detector (1000 spectra per second), an

ultra-fast 1µs shutter and a very large collection angle due to the 5mm entrance aperture (in EELS mode), STEM-SI can be recorded with high resolution with an incredible speed to match with actual high probe current probe. Real EELS is now achievable via dual-EELS. DualEELS™ allows the operator to acquire two optimized EELS spectra from different energy ranges (typically one core-loss and one low-loss) in rapid succession. By having both the core-loss and the low-loss signal from the identical area of the sample, absolute quantification can be performed.. The new precision offset of up to 2kV and switching times less than 50µs allows hysteresis free energy offsets beyond the Si-K edge enabling accurate core level shifts to be measured for elements across the periodic table.

EFTEM performance are critically improved too with an increased field of view up to 36 µm (with a 9mm entrance aperture) allowed by dodecapole based electron-optics. The new image filter offers with an isochromaticity as low as 1eV at 200keV and 0.75% maximum image distortion and of course. Moreover, EFTEM measurement can be done easily with a new automapping software choosing all the measurement parameters to get the best data with the minimum electron radiation as shown on fig.1.

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AMTC Letters Vol. 2 (2010)

© 2010 Japan Fine Ceramics Center

FIG 1. EFTEM elemental mapping using a new automap softwareefficiency, the software estimate the best binning and acquisition time during a prethis example the total acquisition time is 9min 55s with an actual exposure of 7min 32. The pre-exposure and the processing t

FIG 2. Example of spectra acquired using the fast shutter. The low loss and the core loss (>1800eV) were recorded with the same illumination and quasi simultaneously with DualEELS (120µs between the two acquisition) References

[1] P. J. Thomas and P.A. Midgley,

EFTEM elemental mapping using a new automap software1. To increase the overall dose efficiency, the software estimate the best binning and acquisition time during a prethis example the total acquisition time is 9min 55s with an actual exposure of 7min 32. The

exposure and the processing time to set all the parameters took only 1min 22s.

. Example of spectra acquired using the fast shutter. The low loss and the core loss (>1800eV) were recorded with the same illumination and quasi simultaneously with DualEELS (120µs between

P. J. Thomas and P.A. Midgley, Ultramicroscopy 88 (2001) 187–194

To increase the overall dose

efficiency, the software estimate the best binning and acquisition time during a pre-acquisition. In this example the total acquisition time is 9min 55s with an actual exposure of 7min 32. The

ime to set all the parameters took only 1min 22s.

. Example of spectra acquired using the fast shutter. The low loss and the core loss (>1800eV)

were recorded with the same illumination and quasi simultaneously with DualEELS (120µs between

194

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AMTC Letters Vol. 2 (2010)

© 2010 Japan Fine Ceramics Center