Materials Australia – Instrumentation Expo

Come along to a free industry event

Materials Inspection and Instrumentation Expo
MIIX2021

Monday 10 May 2021

12 noon to 5 pm followed by BBQ and then WA Branch Technical Presentation at 6:30pm
Bentley
Innovation Central, Building 216, Curtin University, Bentley Campus

Materials Australia and Innovation Central are inviting science, engineering and technical professionals, academics and students to visit the MIIX2021 expo. The MIIX expo is a free half-day event followed by a technical presentation by Materials Australia. Some of the leading Inspection and Instrumentation equipment suppliers will be showcasing their latest technology and the event is aimed at promoting strong contacts within the Western Australian materials science and technology sector. MIIX2021 is free entry and open to all of our corporate and standard members as well as academics, students and other interested delegates from our kindred societies and Curtin University.

Members of Materials Australia and kindred societies are also encouraged to bring along a “friend” or fellow industry professional to extend this to a networking event and opportunity to meet fellow materials science professionals and encourage new membership.

Bookings prior to the event are preferred to ensure we are properly catered for, so please follow the link to the Trybooking site below and register.

https://www.materialsaustralia.com.au/BookingRetrieve.aspx?etype=BookingID&ID=121463&nm=&m=

 

X-ray Diffraction (XRD)

.. X-ray Diffraction (XRD) is a technique that is utilized to identify crystalline phases present in a given sample.

For powder diffraction, a micronized sample is pressed into a specialised holder and placed into the X-ray Diffractometer. The instrument bombards the powdered sample with X-rays at varying angles. As the X-rays come into contact with the particulate material, they are diffracted by the crystal structure of the phase or phases that are being analysed. The scan results in a diffraction pattern which contains numerous peaks or humps.

 

Figure 1: Raw scan yet to be interpreted

The resulting peaks or humps are similar to a fingerprint, as they can be matched to specific mineral or crystalline phases. The interpretation of the diffraction pattern is a comparative method where the data is matched to an exhaustive list of reference patterns. By using this interpretation technique, it is possible to identify well over ten different minerals or crystalline phases within an unknown  sample, as long as they are present in concentrations that exceed ~1%.

 

Figure 2: Interpreted scan

Note that elemental composition is not determined by XRD, but can be inferred from the phases identified. Confidence in matching the phases can vary depending on how closely the standardised database pattern match the minerals present in the sample, the number and type of other phases present in the sample, crystallinity, concentration of the individual phases and the quality of the diffraction pattern as well as the grinding/micronizing process itself.

Other information than can be gleaned from a diffraction pattern includes the degree of weathering or alteration, crystallite size, elemental substitution, the degree of disorder, and the amorphous content.

The use of elemental assay information (say from XRF) , sample history and geology/location information and complimentary techniques all assist by strengthening confidence in making phase identification more accurate.

Quantification XRD techniques vary from qualitative (what is present) to semi quantitative (what and relative abundance of what is present) through to fully Quantitative Rietveld analysis.

One of the most challenging areas for phase identification is clay speciation. Due to the poor crystallinity and irregular orderingof some clay groups, identification may require additional sample preparation methods including glycolation, heat (dehydration) and other techniques.

At Microanalysis we have several automated powder X-ray Diffractometers. Utilising a number of diffraction databases including the latest 2019 complete International Centre for Diffraction Database (ICDD) to assist in the accurate analysis of unknown samples.  We have a myriad of different holding mounts to assist in the analysis of the samples including our standard holders that utilise approximately one cubic centimetre of powdered sample, holders that take milligram quantities of sample, holders that can present filter cloth, flat ceramic or metallic plates and holders that can accommodate some sample irregularity.

The techniques we frequently utilise are:

Microanalysis Australia is always pleased to customise XRD techniques to accommodation specific client requirements and achieve the highest quality results.

NATA Accredited – Asbestos Testing Using SEM/EDS

Microanalysis Australia is excited and proud to announce that we are the first, and currently only laboratory within Australia to gain NATA accreditation for asbestos and inorganic fibre identification using SEM/EDS.

For the past 11 years we have been helping our clients detect potentially harmful asbestos fibres not identifiable or observable by the PLM method. We have developed a reliable and proven technique using scanning electron microscopy over the past 11 years and, over the past twelve months, we have been working tirelessly and closely with NATA representatives to have our in-house technique recognised.

Gaining accreditation for this technique has been a rewarding and educational process, and we are extremely happy to see this technique officially recognised by NATA.

Please contact us on +61 89225 5810 or admin@microanalysis.com.au to discuss how we can help you today.

Microanalysis – NATA Accredited Laboratory

Microanalysis Australia is pleased to announce they are now a NATA Accredited facility offering the following services under ISO/IEC 1702 (2018):

Contact the laboratory today if you wish to discuss our testing capabilities on +61 8 9225 5810 or admin@microanalysis.com.au

 

XRD – What Is It & How Can It Help You?
X-Ray Diffraction (XRD) is a technique for examining the arrangement of atoms in a crystal lattice. This is a comparative technique where the pattern obtained for a sample is compared against standards collected over the hundred year history of the technique. Elemental composition is not determined by this technique but can be inferred from the results. Confidence in matching the phases can vary depending on how closely the database pattern matches the fraction present in the sample, the number and type of other phases present in the sample, crystallinity, concentration of the phase and the quality of the XRD trace.

Other information that can be gleaned from an XRD trace includes the degree of weathering or alteration, crystallite size, substitution, degree of disorder and the amorphous content.

In real world samples it is common to have over a dozen different crystal phases at varying concentrations in a complex sample. The use of elemental assay, information of the samples history and location and complimentary techniques all assist by strengthening confidence in making phase identification.

XRD techniques vary from qualitative to semi quantitative through to full Quantitative Rietveld analysis. Each technique will deliver different levels of accuracy and precision proportional to the amount of work required to improve accuracy through sample preparation, instrument running and analysis.

One of the most challenging areas for phase identification is clay speciation. Due to the poor crystallinity and irregular ordering of some clay groups, identification may require further work involving glycolation, heat and other techniques.

At Microanalysis we have several automated powder X-ray Diffractometers. We have a number of diffraction databases including the latest 2018 complete International Centre for Diffraction Database (ICDD). Our standard holders take approximately one cubic centimetre of powdered sample. We also have holders that take milligram quantities of sample, holders that can present filter cloth, flat ceramic or metallic plates and holders that can accommodate some sample irregularity.

The techniques we frequently utilise are:

  • Qualitative XRD where the phase identification is conducted and the minerals are classified as major, minor and trace.
  • Semi-quantitativein which the phase identification includes a concentration which is calculated using the normalized reference intensity ratio method where the intensity of the 100% peak divided by the published I/Ic value for each mineral phase is summed and the relative percentages of each phase calculated based on the relative contribution to the sum. An estimation of the amorphous content can also be given.
  • Spiked semi-quantitative which is similar to a standard semi quant with a higher confidence in the concentration values and the estimate of the amorphous content.
  • Quantitative XRD analysis using an internal standard, with Rietveld analysis to give the highest confidence possible in the concentration of phases and amorphous content determined.
  • Crystalline silica determinations for alpha quartz, cristobalite and tridymite. A full phase identification is performed to check for overlaps that may be present from phases present. A specific peak scan is then performed with this result compared against a five point calibration curve to produce a value of each crystalline silica phase present.
  • Clay speciation. A Semi-quantitative analysis is performed followed by gylcolation and heating to determine specific clay groups.
  • Respirable free silica determination. A semi-quantitative analysis is performed on the respirable fraction and is combined with particle size determination and is checked using scanning electron microscopy.
  • Comparative XRD. If there is no entry in the databases for the compound you examining but you’re have or can construct a suitable reference pattern standard, then this technique would still be of value to you.
  • Specific mineral semi-quantitative analysis. The phase(s) of interest are concentrated through solvent washing, heavy liquid separation, magnetic separation or other specific techniques to give better confidence in the identification or to enhance XRD features to study substitution.
Microanalysis is always pleased to customise XRD techniques to accommodation specific requirements and samples to achieve the highest quality results to meet the price point of the client.

Ian Davies – Analytical Scientist

  • NATA
  • Australian Institute of Petroleum
  • Australian X-Ray Analytical Association
  • Royal Australian Chemical Institute
  • Telstra Business Awards
  • Scientific Partners Australia