Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-12-01T04:33:09.831Z Has data issue: false hasContentIssue false
  • English
  • Français

The Role of Simulation in ALCHEMI

Published online by Cambridge University Press:  02 July 2020

Chris Rossouw
Chris Rossouw*
Affiliation:
CSIRO Manufacturing Science & Technology, Private Bag 33, Clayton South MDC, Australia3169
Get access

Abstract

Contrast in zone axis channelling patterns, formed by variations in characteristic X-ray emission rates as an electron beam is scanned in angle, is related to projected sublattice site symmetries of ionized atoms within the unit cell. Whereas overall Brillouin zone geometry is identical to that observed in large angle convergent beam patterns, this incoherent X-ray channelling contrast is related to ADF or BSE contrast by integration over thickness of the signal generated within the specimen. Contrast is thus relatively stable and easily interpretable.1 This is useful in separating the response of dilute atoms from abundant atomic species, since the specific channelling pattern of each atom has its own overall fingerprint. Correlation of patterns formed from Ta-doped TiAl with bright field LACBED is shown in Fig. 1 (clearly Ta occupies Ti sublattice sites). No simulation of channelling contrast is necessary if minority atomic species are distributed over sublattice sites in a way that can be reconstructed from a linear superposition of majority (or host) atom sites that form part of the regular lattice structure. The distribution over sublattice sites may be determined by any one of a variety of analysis methods.2,3

Type
Atom Location by Channeling Enhancement of X-Ray and EELS Signals (ALCHEMI)(organized by J.Spence)
Information
Microscopy and Microanalysis , Volume 7 , Issue S2: Proceedings: Microscopy & Microanalysis 2001, Microscopy Society of America 59th Annual Meeting, Microbeam Analysis Society 35th Annual Meeting, Long Beach, California August 5-9, 2001 , August 2001 , pp. 352 - 353
Copyright
Copyright © Microscopy Society of America 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.)Rossouw, C.J., Ultramicroscopy 58 (1995) 211.CrossRefGoogle Scholar
2.)Rossouw, C.J., Forwood, C.T., Gibson, M.A. and Miller, P.R., Phil Mag A74 (1996) 57.CrossRefGoogle Scholar
3.)Anderson, I.M., 1997, Acta Mater. 45 (1997) 3897.CrossRefGoogle Scholar
4.)Rossouw, C.J., Forwood, C.T., Gibson, M.A. and Miller, P.R., Micron 28 (1997) 125.CrossRefGoogle Scholar
5.)Rossouw, C.J. and Miller, P.R., Journal of Electron Microscopy 48 (1999) 849.CrossRefGoogle Scholar
6.)Rossouw, C.J., Bettles, C.J., Davis, T.J., Forwood, C.T., Miller, P.R. and Venkatesan, K., Acta Cryst (in press)Google Scholar
7.)Saitoh, K., Tanaka, M., Tsai, A-P and Rossouw, C.J., J. Phys. Soc. Japan 69 (2000) 2379.CrossRefGoogle Scholar