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X-ray Diffractometer (XRD)

Overview

Thumbnail image of X-ray Diffractometer (XRD) X-ray diffraction (XRD) is a non-destructive analytical technique used to identify the atomic and molecular structure of crystalline materials. By measuring the diffraction pattern of X-rays scattered at specific angles, the diffractometer determines crystalline phases, structural properties, lattice parameters, and grain sizes. Identification of minerals and mineral proportions can be made on powdered samples of clay, sediment, and rocks.

Instrument Make and Model

Bruker AXS D6 PHASER

Estimated Measurement Time

  • Sample Preparation: 1–3 days
  • Sample Measurement: 30–90 min/sample

Quantity of Sample Material

1–5 grams per sample

Principles & Analytical Capabilities

The D6 Phaser X-ray diffractometer operates by illuminating a sample with an incident X-ray beam at variable angles of incidence(θ), while the diffracted radiation is collected by a coupled detector as a function of the diffraction angle (2θ) relative to the incident beam. The instrument is equipped with a θ/θ goniometer and is configured in a para-focusing Bragg-Brentano geometry, making it well suited for powder diffraction analyses.

The instrument is fitted with a LYNXEYE XE-T detector, which can be operated in either high count-rate or high-resolution modes. In this configuration, electronic filtering is used to discriminate between Cu Kα radiation and unwanted wavelengths, resulting in a significant reduction in background signal and improved signal-to-noise ratios.

The D6 Phaser supports a wide range of qualitative and semi-quantitative X-ray diffraction analyses. Typical applications include phase identification of crystalline materials using reference databases, comparative analysis of mineralogical or crystalline phase composition between samples, and assessment of phase purity. The instrument is suitable for the analysis of powdered materials, sediments, hard rock samples prepared as powders, and clay-rich samples, including oriented mounts for clay mineral identification.

The D6 Phaser is equipped with a 12-position automatic sample changer, allowing up to twelve samples mounted in 32 mm sample rings to be measured sequentially without user intervention, enabling efficient and reproducible high-throughput analysis.

Data Generated

Data components:

  • Intensity (counts)
  • Diffraction angle (2θ)

Data files:

  • XRD Data (BRML): Bruker format files used to store XRD data. Can be processed in Bruker EVA and TOPAS software packages, or with open source XRD software such as Profex.
  • XRD (RAW): file containing raw XRD data and metadata.

Data Example

Graph of X-ray diffraction results for a bulk sediment sample from Hole U1553C of IODP Expedition 378 on the Campbell Plateau in the southern Pacific Ocean.
X-ray diffraction results for a bulk sediment sample from Hole U1553C of IODP Expedition 378 on the Campbell Plateau in the southern Pacific Ocean.1

Procedures & Manuals

References

1  Röhl, U., Thomas, D. J., Childress, L. B., Anagnostou, E., Ausín, B., Boscolo Galazzo, F., Dias, B. B., Brzelinski, S., Dunlea, A. G., George, S. C., Haynes, L. L., Hendy, I. L., Jones, H. L., Khanolkar, S. S., Kitch, G. D., Lee, H., Raffi, I., Reis, A. J., Sheward, R. M., … Hollis, C. J. (2022). IODP Expedition 378 X-ray diffraction (XRD) [Data set]. International Ocean Discovery Program. https://doi.org/10.5281/zenodo.10810054