TEM

Thin film sample prep for Cross sectional TEM (XTEM)

I was tasked with imaging my thin film oxide sample grown on crystalline substrates, but had no access to the latest and greatest sample prep equipment (read: million dollar dual beam FIB) So I was able to figure out some procedures for this using the old school method, with a much less expensive VCR dimpler (Gatan also makes one) and a dual ion mill. It is such a chore that I came up with a handy manual that my other lab-mates find helpful, and wanted to post it for anyone else in the community who finds themselves in my situation.

Zirconolite diffuse diffraction spots- corresponding HREM

Zirconolite diffuse diffraction spots- corresponding HREM

Corresponding HREM of Kr irradiated zirconolite at high temperature.
The diffuse diffraction spots are attributed to the short-range-order domains.

Reference: S.X. Wang, L.M. Wang and R.C. Ewing (1999) TEM study of short-range-order in zirconolite induced by high temperature ion irradiation. Microscopy and Microanalysis, vol. 5, supplement 2, 756-757.

natrolite under 200 keV electron irradiation

natrolite under 200 keV electron irradiation

Bubbles formed in natrolite (a type of naturally occurring zeolite) under 200 keV electron irradiation.
Following amorphization, this zeolite formed bubbles under the focused electron beam which presumably was caused by the combined results of collapse of the internal channels upon amorphization and the release of water from the zeolite structure

zeolite-Y, absense of bubble under e-beam

zeolite-Y, absense of bubble under e-beam

200 keV electron irradiation produced no bubbles on zeolite-Y. This image was after the grain has become amorphous due to e-beam irradiation.
In contrast to many other zeolites (such as analcime and natrolite), zeolite-Y does not form bubble under strong e-beam. The absence of bubbles in irradiated zeolite-Y was attributed to the relatively large aperture size of the internal channel of the structure and the possible preservation of channels after amorphization.

analcime under 200 keV electron irradiation

analcime under 200 keV electron irradiation

Bubbles formed in analcime (a type of zeolite) under 200 keV electron irradiation at room temperature.
Bubbles are due to the release of H2O trapped within analcime. The passage with analcime structure is not large enough for fast release of H2O, thus the bubbles are formed. In contrast, zeolite-Y does not fom bubble under e-beam - due to its large channels linking the structural cavities.

Zeolite - SAD sequence during e-beam irradiation

Zeolite - SAD sequence during e-beam irradiation

Electron diffraction patterns showing the progressive change from crystalline to amorphous state under 200 keV electron irradiation.

Zeolite Y, HREM#4

Zeolite Y, HREM#4

After a certain dose of 200 keV electron beam. The zeolite-Y grain becomes totally amorphous.

Zeolite Y, HREM#3

Zeolite Y, HREM#3

With more e-beam irradiation. The zeolite-y grain becomes partial crystalline and partial amorphous.

Zeolite Y, HREM#2

Zeolite Y, HREM#2

After a certain e-beam irradiation (200 keV), the lattice is starting blurred. Suggesting structural damage.

Zeolite Y HREM

Zeolite Y HREM

Lattice image of zeolite-Y. Zeolite-Y is really sensitive to electron beam irradiation. Operation needs to be quick to get the HREM image.
The zeolite-Y crystal is on carbon film.

ION IRRADIATION EFFECTS FOR TWO PYROCHLORE COMPOSITIONS: Gd2Ti2O7 AND Gd2Zr2O7

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S. X. Wang*, L. M. Wang*, R. C. Ewing* and K. V. Govindan Kutty**, *Department of Nuclear Engineering & Radiological Sciences, The University of Michigan, Ann Arbor, MI, USA **Materials Chemistry Division, Indira Gandhi Center for Atomic Research, Kalpakkam 603 102, India

Electron irradiation of zeolites

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Shixin Wang, Lumin Wang and Rod C. Ewing Department of Nuclear Engineering & Radiological Sciences, The University of Michigan, Ann Arbor, MI, USA.


Presentation given at: Materials Research Society fall meeting, Boston, MA, 1998. Reference: S.X. Wang, L.M. Wang and R.C. Ewing (1999) Electron irradiation of zeolites. Microstructural Processes in Irradiated Materials, S.J. Zinkle, G.E. Lucas, R.C. Ewing and J.S. Williams, Editors, Symposium Proceedings of the Materials Research Society, vol. 540, 361-366.

Diagram of a basic TEM structure

Diagram of a basic TEM structure

Diagram outlining the internal components of a basic TEM system.

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