Imaging of metallic nano-particles using plasmon/valence energy loss electrons
- Georgia Inst. of Tech., Atlanta, GA (United States). School of Materials Science and Engineering
- Oak Ridge Inst. for Science and Education, TN (United States)
Although crystal lattices can be determined reasonably well using high-resolution electron microscopy, determination of local chemistry at high spatial-resolution remains a challenge. An energy-filtering system has made it possible to perform chemically sensitive imaging in a transmission electron microscopy (TEM). This type of imaging usually relies on the signal of the inner shell ionization edge, the intensity of which is affected by the threshold energy-loss and the ionization cross-section of the edge. Therefore, the spatial resolution of a core loss image is strongly affected by the signal-to-noise ratio. In this respect, lower loss electrons from the plasmon or valence region of the energy loss spectrum (10--100 eV) are favorable for chemically sensitive imaging due to the much higher signal intensity, provided any delocalization effects are small in comparison to the required spatial resolution. Compositionally sensitive imaging using the aluminum plasmon energy-loss electrons has been shown to produce {approximately}2nm resolution for an atomically sharp Al/Ti interface. Using this resolution result the reason for the compositional contrast seen in an ion implanted specimen is postulated. The sputter deposited Al/Ti polycrystalline multilayer specimen was imaged using a JEOL 3010 TEM at 300 kV equipped with a Gatan Imaging Filter (GIF{trademark}). The implanted alumina sample was imaged with a GIF{trademark} interfaced to a Philips CM30 TEM operated at 300 keV. The low-loss images were gain normalized, 512 x 512 pixels in size and were recorded with an exposure time of 1 second and an energy-selecting window of 5 eV.
- Research Organization:
- Oak Ridge National Lab., TN (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (United States)
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 505352
- Report Number(s):
- CONF-970834--9; ON: DE97005258
- Country of Publication:
- United States
- Language:
- English
Similar Records
Spectrum lines across planar interfaces by energy-filtered TEM
Quantitative energy-filtered TEM imaging of interfaces