Abstract
The relatively recent entry of field emission electron microprobes into the field of microanalysis provides another tool for the study of small features of interest (e.g., mineral and melt inclusions, exsolution lamellae, grain boundary phases, high-pressure experimental charges). However, the critical limitation for accurate quantitative analysis of these submicrometer- to micrometer-sized features is the relationship between electron beam potential and electron scattering within the sample. To achieve submicrometer analytical volumes from which X-rays are generated, the beam accelerating voltage must be reduced from 15–20 to ≤ 10 kV (often 5 to 7 kV) to reduce the electron interaction volume from ~3 to ~0.5 μm in common geological materials. At these low voltages, critical Kα X-ray lines of transition elements such as Fe are no longer generated, so L X-ray lines must be used. However, applying the necessary matrix corrections to these L lines is complicated by bonding and chemical peak shifts for soft X-ray transitions such as those producing the FeLα X-ray line. It is therefore extremely challenging to produce accurate values for Fe concentration with this approach. Two solutions have been suggested, both with limitations. We introduce here a new, simple, and accurate solution to this problem, using the common mineral olivine as an example. We also introduce, for the first time, olivine results from a new analytical device, the Extended Range Soft X-ray Emission Spectrometer.
Acknowledgments and Funding
We thank the following for providing a second set of olivines for testing the calibration curve: Noriko Kita, Mike Spicuzza, and Kohei Fukuda. The authors thank the two reviewers for their detailed comments which helped make the manuscript more complete. Support for this research came from the National Science Foundation: EAR13-37156 (J.H.F.), EAR15-54269 (J.H.F.), and EAR-1625422 (A.V.D.H.).
References cited
Anderson, C.A. (1967) The quality of X-ray microanalysis in the ultra-soft X-ray region. British Journal of Applied Physics, 18, 1033–1043.10.1088/0508-3443/18/8/301Search in Google Scholar
Anderson, C.A., and Hasler, M.F. (1966) Extension of electron microprobe techniques to biochemistry by the use of long wavelength X-rays. In R. Castaing, P. Deschamps, and J. Philibert, Eds., Proceedings of the Fourth International Conference on X-ray Optics and Microanalysis, p. 310–327. Hermann, Paris.Search in Google Scholar
Barker, F., Wones, D.R., Sharp, W.N., and Desborough, G.A. (1975) The Pikes Peak batholith, Colorado Front Range, and a model for the origin of the gabbro–anorthosite–syenite–potassic granite suite. Precambrian Research, 2, 97–160.10.1016/0301-9268(75)90001-7Search in Google Scholar
Barkshire, I., Karduck, P., Rehbach, W.P., and Richter, S. (2000) High-spatial-resolution low-energy electron beam X-ray microanalysis. Microchimica Acta, 132, 113–12810.1007/s006040050052Search in Google Scholar
Bence, A.E., and Albee, A.L. (1968) Empirical correction factors for the electron microanalysis of silicates and oxides. Journal of Geology, 76(4), 382–403.10.1086/627339Search in Google Scholar
Bertin, E.P. (1975) Principles and Practice of X-ray Spectrometric Analysis, 1079 p. Plenum Press.10.1007/978-1-4613-4416-2Search in Google Scholar
Buse, B., and Kearns, S. (2015) Importance of carbon contamination in highresolution (FEG) EPMA of silicate minerals. Microscopy and Microanalysis. 21, 594–605. 10.1017/S1431927615000288.Search in Google Scholar
Buse, B., and Kearns, S. (2018) Quantification of olivine using Fe La in electron probe microanalysis (EPMA). Microscopy and Microanalysis. 24, 1–7. 10.1017/S1431927618000041.Search in Google Scholar
Castaing, R. (1952) Application des sondes électroniques à une méthode ďanalyse ponctuelle chimique et cristallographique. Ph.D. thesis, Université de Paris, France. (Publication ONERA no. 55)Search in Google Scholar
Castaing, R. (1955) Application of Electron Probes to Local Chemical and Crystallographic Analysis (Application des sondes électroniques à une méthode ďanalyse ponctuelle chimique et cristallographique). Translation by Pol Duwez and David B. Wittry, California Institute of Technology. (http://www.microprobe.org/history/Castaing-Thesis-clearscan.pdf/view)Search in Google Scholar
Castaing, R. (1960) Electron probe microanalysis. In M. Marton, Ed., Advances in Electronics and Electron Physics, p. 317–386. Academic.10.1016/S0065-2539(08)60212-7Search in Google Scholar
Castaing, R., and Fredriksson, K. (1958) Analyses of cosmic spherules with an X-ray microanalyser. Geochimica et Cosmochimica Acta, 14, 114–117.10.1016/0016-7037(58)90099-1Search in Google Scholar
Donovan, J., Kremser, D., Fournelle, J., and Goemann, K. (2018) Probe for Windows User’s Guide and Reference, Enterprise Edition. Probe Software, Inc., Eugene, Oregon.Search in Google Scholar
Duncumb, P. (1960) Improved resolution with X-ray scanning microanalyser. In A. Engstrom, V. Cosslett, and H. Pattee, Eds., X-ray Microscopy and X-ray Microanalysis, Proceedings of 2nd International Symposium, 365–371. Elsevier, Amsterdam.Search in Google Scholar
Fialin, M., Wagner, C., and Pascal, M-L. (2011) Iron speciation using electron microprobe techniques: application to glassy melt pockets within a spinel lherzolite xenolith. Mineralogical Magazine, 75, 347–362.10.1180/minmag.2011.075.2.347Search in Google Scholar
Finch, C.B., Clark, G.W., and Kopp, O.C. (1980) Czochralski growth of singlecrystal fayalite under controlled oxygen fugacity conditions. American Mineralogist, 65, 381–389.Search in Google Scholar
Fournelle, J.H. (1988) The geology and petrology of Shishaldin Volcano, Unimak Island, Aleutian Islands. Ph.D. thesis, Johns Hopkins University, Baltimore.Search in Google Scholar
Fournelle, J., Cathey, H., Pinard, P.T., and Richter, S. (2016) Low voltage EPMA: experiments on a new frontier in microanalysis–analytical lateral resolution. In IOP Conference Series: Materials Science and Engineering, 109, 1, 012003. IOP Publishing.Search in Google Scholar
Gopon, P., Fournelle, J., Sobol, P.E., and Llovet, X. (2013) Low-voltage electronprobe microanalysis of Fe–Si compounds using soft X-rays. Microscopy and Microanalysis, 19, 1698–1708.10.1017/S1431927613012695Search in Google Scholar PubMed
Heinrich, K.F.J. (1987) Mass absorption coefficients for electron probe microanalysis. In J.D. Brown and R.H. Packwood, Eds., Proceedings of the 11th international Congress on X-ray Optics and Microanalysis, 67–119. University of Western Ontario Press, London, Ontario.Search in Google Scholar
Hovington, P., Drouin, D., and Gauvin, R. (1997a) CASINO: A new Monte Carlo code in C language for electron beam interaction—Part I: Description of the program. Scanning, 19, 1–14.10.1002/sca.4950190101Search in Google Scholar
Hovington, P., Drouin, D., Gauvin, R., and Joy, D.C. (1997b) Parameterization of the range of electrons at low energy using the CASINO Monte Carlo program. Microscopy and Microanalysis, 3, 885–886.10.1017/S1431927600011314Search in Google Scholar
International Organization for Standardization (2003) Microbeam analysis—Electron probe microanalysis—Guidelines for the determination of experimental parameters for wavelength dispersive spectroscopy. ISO 14594.Search in Google Scholar
Jarosewich, E., Nelen, J.A., and Norberg, J.A. (1980) Reference samples for electron microprobe analysis. Geostandards Newsletter, 4(1), 43–47.10.1111/j.1751-908X.1980.tb00273.xSearch in Google Scholar
Kearns, S., Buse, B., and Wade, J. (2014) Mitigating thermal beam damage with metallic coats in low voltage FEG-EPMA of geological materials. Microscopy and Microanalysis, 20(S3), 740–741.10.1017/S143192761400542XSearch in Google Scholar
Keil, K., and Fredriksson, K. (1964) The iron, magnesium, and calcium distribution in coexisting olivines and rhombic pyroxenes of chondrites. Journal of Geophysical Research, 69(16), 3487–3515.10.1029/JZ069i016p03487Search in Google Scholar
Li, X., Zhang, C., Almeev, R.R., Zhang, X-C., Zhao, X-F., Wang, L-X., Koepke, J., and Holtz, F. (2019) Electron probe microanalysis of Fe2+/ΣFe ratios in calcic and sodic-calcic amphibole and biotite using the flank method. Chemical Geology, 509, 152–162.10.1016/j.chemgeo.2019.01.009Search in Google Scholar
Libourel, G., and Portail, M. (2018) Chondrules as direct thermochemical sensors of solar protoplanetary disk gas. Science Advances, 4(7), p.eaar3321.10.1126/sciadv.aar3321Search in Google Scholar PubMed PubMed Central
Llovet, X., and Galan, G. (2003) Correction of secondary X-ray fluorescence near grain boundaries in electron microprobe analysis: Application to thermobarometry of spinel lherzolites. American Mineralogist, 88, 121–130.10.2138/am-2003-0115Search in Google Scholar
Llovet, X., and Salvat, F. (2016) PENEPMA: a Monte Carlo programme for the simulation of X-ray emission in EPMA. In IOP Conference Series: Materials Science and Engineering, 109, 1, 012009. IOP Publishing.Search in Google Scholar
Llovet, X., Heikinheimo, E., Galindo, A.N., Merlet, C., Bello, J.A., Richter, S., Fournelle, J., and Van Hoek, C.J.G. (2012) An inter-laboratory comparison of EPMA analysis of alloy steel at low voltage. In IOP Conference Series: Materials Science and Engineering, 32, 1, 012014. IOP Publishing.10.1088/1757-899X/32/1/012014Search in Google Scholar
Llovet, X., Pinard, P.T., Heikinheimo, E., Louhenkilpi, S., and Richter, S. (2016) Electron probe microanalysis of Ni silicides using Ni-L X-ray lines. Microscopy and Microanalysis, 22, 1233–1243.10.1017/S1431927616011831Search in Google Scholar PubMed
McSwiggen, P. (2014) Characterisation of sub-micrometre features with the FE-EPMA. In IOP Conference Series: Materials Science and Engineering, 55, 1, 012009. IOP Publishing.10.1088/1757-899X/55/1/012009Search in Google Scholar
Merlet, C., and Llovet, X. (2012) Uncertainty and capability of quantitative EPMA at low voltage—A review. In IOP Conference Series: Materials Science and Engineering, 32, 1, 012016. IOP Publishing.10.1088/1757-899X/32/1/012016Search in Google Scholar
Moy, A., Fournelle, J.H., and von der Handt, A. (2019) Quantitative measurement of iron-silicides by EPMA using the Fe Lα and Lβ X-ray lines: a new twist to an old approach. Microscopy and Microanalysis, 25, 664–674. 10.1017/S1431927619000436Search in Google Scholar PubMed
Pinard, P.T., and Richter, S. (2016) Quantification of low concentration elements using soft X-rays at high spatial resolution. In IOP Conference Series: Materials Science and Engineering, 109, 1, 012013. IOP Publishing10.1088/1757-899X/109/1/012013Search in Google Scholar
Pouchou, J.L. (1996) Use of soft X-rays in microanalysis. Mikrochimica Acta 13(Suppl.), 39–60.10.1007/978-3-7091-6555-3_3Search in Google Scholar
Pouchou, J.L., and Pichoir, F. (1991) Quantitative analysis of homogeneous or stratified microvolumes applying the model “PAP”, In K.F.J. Heinrich and D.E. Newbury, Eds., Electron Probe Quantitation, p. 31–75. Plenum Press.10.1007/978-1-4899-2617-3_4Search in Google Scholar
Reed, S.J.B. (1966) Spatial resolution in electron probe microanalysis. In R. Castaing, P. Deschamps, and J. Philibert, Eds., Proceedings of the Fourth International Conference on X-ray Optics and Microanalysis, p. 339–349. Hermann, Paris.Search in Google Scholar
Rémond, G., Myklebust, R., Fialin, M., Nockolds, C., Phillips, M., and Roques-Carmes, C. (2002) Decomposition of wavelength dispersive X-ray spectra. Journal of Research of the National Institute of Standards and Technology, 107, 509–529.10.6028/jres.107.044Search in Google Scholar PubMed PubMed Central
Ritchie, N.W. (2011) Getting Started with NIST DTSA-II. Microscopy Today, 19(1), 26–31.10.1017/S155192951000132XSearch in Google Scholar
Rose, T. R., Sorensen, S.S., and Post, J.E. (2009) The impurities in the Rockport fayalite microbeam standard: How bad are they? American Geophysical Union, Fall Meeting 2009, abstract V31E-2008.Search in Google Scholar
Salvat, F., Fernandez Varea, J.M., and Sempau, J. (2013) PENELOPE—A code system for Monte Carlo simulation of electron and photon transport. OECD/Nuclear Energy Agency, Issy-les-Moulineaux, France.Search in Google Scholar
Saunders, K., Buse, B., Kilburn, M.R., Kearns, S., and Blundy, J. (2014) Nanoscale characterisation of crystal zoning. Chemical Geology, 364, 20–32.10.1016/j.chemgeo.2013.11.019Search in Google Scholar
Shea, T., Lynn, K.J., and Garcia, M.O. (2015) Cracking the olivine zoning code: Distinguishing between crystal growth and diffusion. Geology, 43, 935–938. 10.1130/G37082.1.Search in Google Scholar
Terauchi, M., and Sato, Y. (2018) Chemical state analyses by soft X-ray emission spectroscopy. JEOL NEWS, 53(1), 30–35.Search in Google Scholar
Terauchi, M., Takahashi, H., Handa, N., Murano, T., Koike, M., Kawachi, T., Imazono, T., Hasagawa, N., Koeda, M., Nagano, T., and Sasai, H. (2011) An extension up to 4 keV by a newly developed multilayer-coated grating for TEM-SXES spectrometer. Microscopy and Microanalysis, 17(S2), 604–605.10.1017/S1431927611003898Search in Google Scholar
Vladár, A.E., and Postek, M.T. (2009) The scanning electron microscope. In J. Orloff, Ed., Handbook of Charged Particle Optics, 2nd ed., p. 437–496. CRC Press.10.1201/9781420045550.ch9Search in Google Scholar
Ziebold, T.O., and Ogilvie, R.E. (1963) Quantitative analysis with the electron microanalyzer. Analytical Chemistry, 35(6), 621–627.10.1021/ac60199a038Search in Google Scholar
Zschornack, G.H. (2007) Handbook of X-Ray Data. Springer-Verlag.Search in Google Scholar
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