| AVS 56th International Symposium & Exhibition | |
| In Situ Microscopy and Spectroscopy: Interfacial and Nanoscale Science Topical Conference | Friday Sessions |
| Session IS+AS-FrM |
| Session: | In-Situ Microscopy and Spectroscopy: Dynamic Nanoscale Processes |
| Presenter: | B. Freitag, FEI Company, The Netherlands |
| Authors: | B. Freitag, FEI Company, The Netherlands D. Stokes, FEI Company, The Netherlands D. Hubert, FEI Company, The Netherlands |
| Correspondent: | Click to Email |
Electron microscopy can provide more than just static observations and characterization of materials. For example, the environmental transmission electron microscope (ETEM) enables the synthesis of materials in the TEM, and allows us to study dynamic behavior under the influence of different gases and temperatures, while maintaining atomic resolution capabilities. By varying the temperature, pressure and composition of the gaseous environment, it is possible to directly interrogate chemical processes using both imaging and spectroscopic techniques. This allows a deep understanding of the mechanisms and kinetics of reactions at the nanoscale, as evidenced by the growing body of literature (see, for example [1-6]).
The most recent addition to the Titan S/TEM family is specifically designed for ETEM studies, with a pressure range of up to 4 kPa (40mbar, 30 torr) of gas at the specimen area and a wide range of temperatures. This special microscope is equipped with a gas sensor and a plasma cleaner and can be operated in non-ETEM mode with the standard sub-Angstrom specifications of a conventional Titan. Figure 1 demonstrates imaging performance for a nitrogen gas pressure p = 500 Pa (5 mbar, 3.75 torr), showing an information transfer of 1.2 Å, obtained for a gold specimen in an aberration-corrected ETEM. In this talk the performance of the ETEM and application results on chemical reactions are presented.
References
[1] R. Sharma and K. Weiss, Microscopy Research and Technique 42(4) (1998), p. 270-280.
[2] P.L. Hansen, J.B. Wagner, S. Helveg, J.R. Rostrup-Nielsen, B.S. Clausen and Topsoe, H., Science 295(5562) (2002) p. 2053-2055.
[3] S. Helveg, C. Lopez-Cartes, J. Sehested, P.L. Hansen, B.S. Clausen, J.R. Rostrup-Nielsen, F. Abild-Pedersen and Norskov, J.K., Nature 427 (2004) p. 426-429.
[4] R. Sharma, P. Rez, M. Brown, G.H. Du, and M.M.J. Treacy, Nanotechnology 18(12) (2007)
[5] S. Hofmann, R. Sharma, C. Ducati, G. Du, C. Mattevi, C. Cepek, M. Cantoro, S. Pisana, A. Parvez, F. Cervantes-Sodi, A.C. Ferrari, R. Dunin-Borkowski, S. Lizzit, L. Petaccia, A. Goldoni and J. Robertson, Nano Letters 7(3) (2007) p. 602-608.
[6] P.L. Gai, R. Sharma and F.M. Ross, MRS Bulletin 33(2) (2008) p. 107-114.