Wavelength Dispersive X-Ray Fluorescence Spectroscopy (WDXRF) Services

Wavelength dispersive x-ray fluorescence spectroscopy (WDXRF) services from Covalent Metrology are one of the most cost-efficient, nondestructive compositional analysis techniques available in the industry.

In a WDXRF measurement, the sample is irradiated with high energy x-rays. This irradiation stimulates the emission of characteristic x-rays associated with elements present in the material. WDXRF spectrometers use Bragg diffraction from crystals within the instrument to produce wavelength-separated peaks, each associated with a specific element. This yields semi-quantitative, and quantitative (if calibrated), information about the elements present in the sample matrix and their atomic ratios. Unlike EDXRF, WDXRF has excellent light element detection capability.

APPLICATION AREAS FOR WDXRF:

WDXRF is most widely used in research and development of materials and quality testing across industries from petroleum/gas to marine and health sciences. It can be used to identify all elements present in a given specimen, and/or to very accurately quantify the content of elements in a sample. As a result of its low cost and high-throughput, WDXRF makes for an easy check in any QA workflow but is robust and accurate enough to occupy a role in environmental and consumer safety evaluations.

Furthermore, the technique leads the field in detection limits for trace elements, the tool can be used to accurately quantify the atomic concentration of certain elements in metallic thin films.

MEASUREMENTS:

  • Identification of all elements (Atomic Number ≥ 4) present in a sample
  • Elemental quantification 
  • Semi-quantitative comparison of the relative concentration of elements present in samples

USES & LIMITATIONS:

  • What it is great for:
    • Very low detection limits, enabling identification of trace elements
    • High resolution compared to EDXRF
    • Excellent reproducibility
    • Minimal sample prep necessary; data collection is quick and straightforward
  • Limitations:
    • High accuracy quantification of values needs calibrated standards.

Example Outputs

Wavelength Dispersive XRF
Increase in resolution through use of wavelength dispersive XRF (our tool is AZX 400, which is wavelength dispersive)
Above figures are qualitative charts of W/Co multi-layer, with 3 different conditions (described above). After 1st etching process, the peak intensity of W-L⍺ becomes smaller than before processing. The W-L⍺ peak disappeared in the sample after the 2nd etching process. It means the W layer decomposed by the two processes. You can also see the Co-K⍺ peak maintains the intensity even after the W layer disappears. From this result, this etching liquid does not influence Co.

The Principle of XRF

Principle of XRF

INSTRUMENTS 

Rigaku AZX 400

Rigaku’s unique AZX400 sequential wavelength dispersive X-ray fluorescence (WDXRF) spectrometer was specifically designed to handle very large and/or heavy samples. Accepting samples up to 400 mm diameter, 50 mm thick and 30 kg weight, this system is ideal for analyzing sputtering targets, magnetic disks, or for multilayer film metrology or elemental analysis of large samples.
© 2020 by Covalent Metrology Services Proudly powered by WordPress