Tables for
Volume H
Powder diffraction
Edited by C. J. Gilmore, J. A. Kaduk and H. Schenk

International Tables for Crystallography (2018). Vol. H, ch. 2.6, p. 150

Section 2.6.2. In situ powder diffraction

C. A. Reissa*

aNoordikslaan 51, 7602 CC Almelo, The Netherlands
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2.6.2. In situ powder diffraction

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The Latin phrase `in situ' literally means `in position', but it is used in many contexts. In the field of X-ray powder diffraction there is no strict definition of this phrase. If the phrase is taken literally, all non-ambient experiments are in situ; the material stays `in position' during the non-ambient experiment. The environment changes while transforming the sample by outside influences (Norby & Schwarz, 2008[link]). Temperature changes give rise to many processes that can be monitored with or without different gas environments. The main processes that are monitored are the formation of new compounds, phase transformations, and structural changes such as lattice expansions and contractions. Increasingly, surface-layer properties such as stress and texture are studied. The characterization of variations in the crystallite size of nanomaterials is a more recent application.

In situ X-ray diffraction is still a growing research field owing to the introduction of line detectors and area detectors (see Chapter 2.5[link] ). These make it possible to measure a large part of the diffraction pattern at once, making the scanning time much shorter compared with a point detector. This speed significantly improves the data quality and reduces the risk of collecting uninterpretable data because of changes in the material under study during the measurement. Another advantage of these detectors is that static detector measurements can be performed, making time-resolved and/or temperature-resolved studies possible.


Norby, P. & Schwarz, U. (2008). Powder Diffraction: Theory and Practice, edited by R. E. Dinnerbier & S. J. L. Billinge, pp. 439–463. Cambridge: Royal Society of Chemistry.Google Scholar

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