Asymmetry of 1 nm XRD Reflection and Measurement of Illite Crystallinity

• Authors: Hejing Wang , Jian Zhou
• Languages of publication: EN

Abstracts

EN

Theoretically the X-ray emission is subjected to the Gaussian distribution and is symmetric. An X-ray diffraction peak should be symmetric, too. However all illite 1 nm (interplanar distance) peaks used for measurement of illite crystallinity (IC) are practically asymmetric. Our experimental results prove that any X-ray diffraction peak in low diffraction angle segment appears asymmetric if the diffractometer is running with a slit-fixed system. However, if the diffractometer is running with an auto-adjustable-slit system and the illumination length is fixed, the X-ray diffraction peak in low diffraction angle segment is symmetric. Those peaks derived from synchrotron radiation are symmetric in all angle ranges. The asymmetric degree (AsD) of a X-ray diffraction peak is subjected to the ratio of integrated intensities on lower and higher diffraction angle sides which are related to the X-ray illuminating length (area) on the sample. From the expression of illuminating length it is derived that with increasing diffraction angle the illuminating length decreases and therefore a X-ray diffraction peak is always asymmetric. The relationship between AsD and IC can be expressed as AsD = 0.239IC + 0.999, When illite/smectite mixed-layer phase presents the asymmetry of the illite 1 nm X-ray diffraction peak will be obviously higher than usual case and induces unusually larger IC value.

Keywords

EN

07.85.Nc; 07.85.Jy; 07.85.Fv

Discipline

• 07.85.Jy: Diffractometers
• 07.85.Nc: X-ray and γ-ray spectrometers
• 07.85.Fv: X- and γ-ray sources, mirrors, gratings, and detectors

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2016
• Volume: 130
• Issue: 4
• Pages: 886-888

Dates

published

2016-10

Contributors

author

Hejing Wang

• X-ray Laboratory, School of Earth and Space Sciences, Peking University, China

author

Jian Zhou

• Chinese Academy of Geological Sciences, China

References

• [1] W.B. Stern, J. Mullis, M. Rahn, M. Frey, Schweiz. Miner. Petrogr. Mitt. 71, 453 (1991)
• [2] B. Lanson, D. Champion, Am. J. Sci. 29l, 473 (1991), doi: 10.2475/ajs.291.5.473
• [3] H.J. Kisch, J. Metamorphic. Geol. 9, 665 (1991), doi: 10.1111/j.1525-1314.1991.tb00556.x
• [4] D.M. Moore, Jr., R.C. Reynolds, in: Quantitative Analysis, 2nd ed., Eds. D.M. Moore Jr., R.C. Reynolds, Oxford University Press, Oxford 1997, p. 102
• [5] H. Wang, J. Zhou, J. Appl. Crystallogr. 33, 1128 (2000), doi: 10.1107/S0021889800006932
• [6] H. Wang, J. Zhou, J. Appl. Crystallogr. 38, 830 (2005), doi: 10.1107/S0021889805024490
• [7] W. Ruland, J. Appl. Crystallogr. 1, 90 (1968), doi: 10.1107/S0021889868005066
• [8] R.K. Nandi, S.P. Sen Gupta, J. Appl. Crystallogr. 11, 6 (1978), doi: 10.1107/S0021889878012595
• [9] L. Alexander, J. Appl. Phys. 19, 1068 (1948), doi: 10.1063/1.1698013
• [10] R.T. Bragg, J.B. Aladekomo, J. Appl. Crystallogr. 28, 14 (1995), doi: 10.1107/S0021889894006333
• [11] M.A.G. Aranda, E.R. Losilla, A. Cabeza, S. Bruque, J. Appl. Crystallogr. 31, 16 (1998), doi: 10.1107/S0021889897006419
• [12] O. Masson, R. Guinebretiere, A. Dauger, J. Appl. Crystallogr. 29, 540 (1996), doi: 10.1107/S0021889896004839
• [13] L.N. Warr, A.H.N. Rice, J. Metamorph. Geol. 12, 141 (1994), doi: 10.1111/j.1525-1314.1994.tb00010.x
• [14] W.N. Schreiner, Powder Diffr. 1, 26 (1986), doi: 10.1017/S0885715600011258
• [15] E. Ferrage, C.A. Kirk, G. Cressey, J. Cuadros, Am. Miner. 92, 994 (2007), doi: 10.2138/am.2007.2396
• [16] H.A. Liebhafsky, H.G. Pfeiffer, P.D. Zemany, Anal. Chem. 27, 1257 (1955), doi: 10.1021/ac60104a014
• [17] Y. Beers, Introduction to the Theory of Error, 2nd ed., Addison-Wesley, Boston 1957, p. 46
• [18] M. Slaughter, in: Electron Microscopy and X-Ray Applications to Environmental and Occupational Health Analysis, Ed. P.A. Russell, Ann Arbor Science, Michigan 1981, Vol. 2, p. 77
• [19] L. Alexander, J. Appl. Phys. 25, 155 (1954), doi: 10.1063/1.1721595
• [20] H.P. Klug, L.E. Alexander, X-ray Diffraction Procedures, 2nd ed., Wiley, New York 1974, p. 291

Identifiers

DOI

10.12693/APhysPolA.130.886