X-ray Diffraction Facility

X-ray diffraction (XRD) is a versatile analytical method that provides important information on material properties. The technique is primarily used for structural study of crystalline solids, and is widely applied across the Earth Sciences to support traditional techniques used to characterise natural and synthetic materials. The method applies a collimated beam of X-rays to the sample, which is diffracted at predictable angles dictated by the spacing between sets of crystallographic lattice planes – each of those showing as a discrete peak in a diffraction pattern.

The Department of Earth Sciences houses a PANalytical Empyrean Series 2 X-ray diffractometer. Our instrument can analyse both powered samples and flat unpulverised samples.

Key Features

  • X-ray Diffraction (2)

    Configured for a range of diffraction experiments in the theta-theta geometry

  • A cobalt X-ray source (well-optimised for iron-rich samples)
  • PIXcel1D detector
  • Programmable divergence and anti-scatter slits
  • Spinner and capillary stages
  • Automated powder sample changer (accommodating up to 48 samples)
  • Flat sample stage allowing in-situ analysis of small areas in larger (<15 x 10 cm) samples (provided surface topography is reasonable)

Applications

  • Mineral identification
    • Rapid (<30 mins) bulk analysis of powdered rocks (all areas of petrology, including economic exploration) with semi-quantitative mineralogical composition estimates using RIR method
    • Discrimination of polymorphs (i.e., varieties of carbonate, serpentine, zeolite or quartz), otherwise challenging to determine using other methods
    • Petroleum and stratigraphy applications including clay speciation
  • Analysis of synthetic or experimental samples for high pressure mineralogy studies (i.e., thin metallic films, sputter coats)
  • Calculating estimated amorphous content (i.e., volcanic glass, organics) in mixed samples

Sample Requirements

Powder samples should be crushed (and sieved) to a particle size fraction of ideally 1 to 20 microns for best results while avoiding over- and under-grinding.

Through the use of silicon single crystal substrates in front-loaded experiments, diffraction data can be acquired on vanishingly small amounts of material.

Bulk powder samples require a flat surface to accommodate accurate measurement. Back-loaded holders are available for improvement of preferred orientation effects.

How We Can Support You

We can offer advice at any stage of the research process, including:

  1. Advice on potential research approaches at the initial stages of inquiry
  2. Logistics and scheduling
  3. Aid in sample preparation 
  4. On-instrument training and support in data collection
  5. Data interpretation using the PANalytical HighScore software, and access to the International Centre of Diffraction Data (ICDD) database on request

Contact Information

Interested in using our X-ray Diffraction Facility?

For rates, training, or to schedule use, please contact Kris Sokół at krzysztof.sokol@earth.ox.ac.uk.