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Analytical Electron Microscopy and the Problem of Potassium Diffusion

Published online by Cambridge University Press:  02 April 2024

Ben A. van der Pluijm ,
Jung Hoo Lee  and
Donald R. Peacor
Ben A. van der Pluijm
Affiliation:
Department of Geological Sciences, University of Michigan, Ann Arbor, Michigan 48109
Jung Hoo Lee*
Affiliation:
Department of Geological Sciences, University of Michigan, Ann Arbor, Michigan 48109
Donald R. Peacor
Affiliation:
Department of Geological Sciences, University of Michigan, Ann Arbor, Michigan 48109
*
2Current address: Department of Geology, Jeonbuk National University, Jeonju, Republic of South Korea.
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Abstract

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Diffusion of K during analytical electron microscopy (AEM) results in anomalously low count rates for this element. As the analysis area and specimen thickness decrease, count rates become disproportionally lower. Adularia and muscovite show different diffusion profiles during AEM; for muscovite a strong dependence of diffusion on crystallographic orientation has been observed. Conditions giving rise to reliable chemical data by AEM are the use of a wide scanning area (>800 × 800 Å) and/or large beam size to reduce the effect of diffusion of alkali elements, a specimen thickness greater than about 1000 Å, constant instrument operating conditions, and the use of a homogeneous, well-characterized standard sample. The optimum thickness range was obtained by determining the element intensity ratio vs. thickness curve for given operating conditions. The standard and unknown should have a similar crystal structure and, especially for strongly anisotropic minerals such as phyllosilicates, a similar crystallographic orientation with respect to the electron beam.

Keywords

AdulariaAnalytical electron microscopyDiffusionMuscovitePotassiumTransmission electron microscopy
Type
Research Article
Information
Clays and Clay Minerals , Volume 36 , Issue 6 , December 1988 , pp. 498 - 504
Copyright
Copyright © 1988, The Clay Minerals Society

Footnotes

1

Contribution 452 of the Mineralogical Laboratory.

References

Ahn, J. H. and Peacor, D. R., 1986 Transmission and analytical electron microscopy of the smectite-to-illite tran-sition Clays & Clay Minerals 34 165 – 179.Google Scholar
Ahn, J. H., Peacor, D. R. and Essene, E. J., 1986 Cation-diffusion-induced characteristic beam damage in transmission electron microscope images of micas Ultramicroscopy 19 375 – 382.CrossRefGoogle Scholar
Allard, L. F., Blake, D. F. and Heinrich, K. F. J., 1982 The practice of modifying an analytical electron microscope to produce clean X-ray spectra Microbeam Analysis—1982 San Francisco San Francisco Press 8 – 19.Google Scholar
Blake, D. F., Allard, L. F., Peacor, D. R., Bigelow, W. C. and Bailey, G. W., 1980 “Ultraclean” X-ray spectra in the JEOL JEM-100CX Proc. 38th Ann. Meeting, Electron Microsc. Soc. Amer., San Francisco, 1980 Baton Rouge, Louisiana Claitor’s Publishing Division 136 – 137.Google Scholar
Cliff, G. and Lorimer, G. W., 1975 The quantitative analysis of thin specimens J. Microsc. 103 203 – 207.CrossRefGoogle Scholar
Craw, D., 1981 Oxidation and microprobe-induced potassium mobility in iron-bearing phyllosilicates from the Ota-go schists, New Zealand Lithos 14 49 – 57.CrossRefGoogle Scholar
Goldstein, J. L., Costley, J. L., Lorimer, G. W., Reed, S. J. B. and Johari, O., 1977 Quantitative X-ray analysis in the electron microscope SEM 1977 Chicago IIT Research Inst. 315 – 324.Google Scholar
Isaacs, A. M., Brown, P. E., Valley, J. W., Essene, E. J. and Peacor, D. R., 1981 An analytical electron microscopy study of a pyroxene-amphibole intergrowth Contrib. Mineral. Petrol. 77 115 – 120.CrossRefGoogle Scholar
Knipe, R. J., 1979 Chemical analysis during slaty cleavage development Bull. Mineral. 102 206 – 210.Google Scholar
Lee, J. H., Peacor, D. R., Lewis, D. D. and Wintsch, R. P., 1986 Evidence for syntectonic crystallization for the mudstone-to-slate transition at Lehigh Gap, Pennsylvania, U.S.A. J. Struct. Geol. 8 767 – 780.CrossRefGoogle Scholar
Lorimer, G. W., 1987 Quantitative X-ray microanalysis of thin specimens in the transmission electron microscope: A review Mineral. Mag. 51 49 – 60.CrossRefGoogle Scholar
Lorimer, G. W., Cliff, G. and Wenk, H.-R., 1976 Analytical electron microscopy of minerals Electron Microscopy in Mineralogy Berlin Springer-Verlag 506 – 519.CrossRefGoogle Scholar
Veblen, D. R. and Buseck, P. R., 1980 Microstructure and reaction mechanism in biopyriboles Amer. Mineral. 65 599 – 623.Google Scholar
White, S. H. and Johnston, D. C., 1981 A microstructural and microchemical study of cleavage lamellae in a slate J. Struct. Geol. 3 279 – 290.CrossRefGoogle Scholar
White, S. H. and Knipe, R. J., 1978 Microstructure and cleavage development in selected slates Contrib. Mineral. Petrol. 66 165 – 174.CrossRefGoogle Scholar