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Controlled Environment [Ecell] Tem for Dynamic In-Situ Reaction Studies with Hrem Lattice Imaging

Published online by Cambridge University Press:  15 February 2011

E D Boyes
Affiliation:
DuPont Company, CR&D, PO Box 80356–383, Wilmington, DE 19880–0356, USA
P L Gai
Affiliation:
DuPont Company, CR&D, PO Box 80356–383, Wilmington, DE 19880–0356, USA
L G Hanna
Affiliation:
DuPont Company, CR&D, PO Box 80356–383, Wilmington, DE 19880–0356, USA
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Abstract

With a controlled environment electron microscope it is possible to remove the effect of another atmosphere, such air, to which the sample may have become exposed; to study in considerable detail the continuous development of a series of microstructures in a dynamic process, to identify important intermediate phases and defects in them which may only be metastable under specific reaction conditions of atmosphere and temperature, and to establish whether they are the origin, or merely the consequence, of the reaction. In this paper we report the extensive modification of a high resolution transmission electron microscope (Philips CM30T HRTEM) to add facilities for dynamic in-situ gas-solid reaction studies in a controlled atmosphere of gas or vapor at pressures of 0–50mbar which replaces the regular high vacuum TEM environment. The new environmental cell (ECELL) capability is combined with the original 0.23nm TEM resolution, STEM (BF/ADF) imaging and chemical and crystallographic analyses. Regular specimen holders are used; including hot stages capable of temperatures >1000°C. The full TEM resolution has been demonstrated at temperatures above 700°C and with limited (mbar) amounts of gas flowing through the integral 4-aperture differentially pumped ECELL (and with the additional pumps for the system operating). The ECELL system can be used to preserve, or if necessary to recreate, a continuous chain of evidence in a chemical reaction process.

Type
Research Article
Copyright
Copyright © Materials Research Society 1996

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References

1. Gai, P L, Catal Rev - Sci & Eng (1992), 34, 1 Google Scholar
2. Sinclair, R, Yamashita, T and Ponce, F A, Nature (1981), 290, 386 Google Scholar
3. Pashley, D W, Stowell, M J, Jacobs, M H and Law, T J, Phil Ma (1964), 10, 127 Google Scholar
4. Yagi, K, Thin Solid Films (1985), 126, 95 Google Scholar
5. Venables, J A, Ultramicroscopy (1980) 5 Google Scholar
6. Butler, E P and Hale, K F, “Dynamic Experiments in the Electron Microscope”, North Holland, Amsterdam, 1981 Google Scholar
7. Double, D D, Hellawel, A and Perry, S J, Proc Roy Soc (1978), A359, 435 Google Scholar
8. Parsons, D F, Science (1974) 186 407 Google Scholar
9. Agar, A W et al, Proc 7th Int Cong EM, Grenoble, 1, 115Google Scholar
10. Swann, P R and Tighe, N, Proc 5th Eur Congr on EM, Manchester, (1972), 436 Google Scholar
11. Doole, R C, Parkinson, G M and Stead, J M, Inst Phys Conf Ser (1991) 119, 161 Google Scholar
12. We thank Emile Asselbergs and Philips Electron Optics NV for expert assistance.Google Scholar