February 2002 Newsletter

Contents

1. Editorial
2. Meeting Survey ( Download Form - Surv2.rtf)Your chance to have a say on topics for future meetings.
3. Newsletter mailing list
4. 22nd Durham Conference on X-Ray AnalysisReport
5. Industrial Group AGM 28 March 2002 Nottingham University -IG Programme
6. Spring Meeting Programme Overview
7. IG Posters and Workshops at Spring Meeting March 2002 Nottingham University
8. Autumn Meeting 1/11/01 Pilkington, Lathom -Report
9. Committee Members and Addresses (2001)

Thanks to Bruker-AXS who sponsored the distribution of the paper edition of this Newsletter.

Forthcoming Events

2002 BCA Spring Meeting - Nottingham University, 25 - 28^th March.

Editorial

Welcome to the latest BCA Industrial Group newsl etter. I hope that everyone had a good Christmas break and has recharged their batteries.

I would encourage as many of you as possible to attend the BCA Spring Meeting in Nottingham. Those of you who have been to previous meetings will know what a good opportunity the meeting provides to get together with fellow crystallographers, not only from the industrial group, but the other groups as well. Note that early registration is cheaper, so get onto the boss!

Please also consider su bmitting a poster for the meeting. Finally, please take time to fill out the survey form enclosed with this newsletter.

Philip Holdway

Editor

Newsletter Mailing list.

To keep cost down and to ensure that the newsletter gets to the appropriate people it is essential that we know your correct address. Also if there is a more appropriate contact in your organisation or if you no longer requ ire a copy please let us know by contacting any of the committee officers.

If you would like an e-mail notification of the WEB posting of future IG Newsletters then send an E-mail to [email protected] - with the title SUBSCRIBE WEB NEWS

Dave Taylor

Durham Conference on X-ray Analysis

September 10-13 2001

The 22^nd International Durham Conference on X-ray Analysis was held at the� University of Durham on 10^th -13^th� September 2001. The conference was organised by Philips Analytical and as in previous years the venue was Durham Castle which has the status of a World Heritage site. The conference was packed with interesting presentations and there was a full XRF programme in addition to the XRD sessions.

The technical programme began with� "A hitchhikers guide to X--ray diffraction and X-ray fluorescence" followe d by sessions devoted to all aspects of these two techniques. Papers presented by Philips representatives included new developments in hardware and software and some of the applications resulting from these applications. Presentations included� "New Instrumentation-New Opportunities, in which Philip Lake, GlaxoSmithKLine showed how the adaptability of the modern diffractometer configuration has aided characterisation and quantification of the various solid state forms of drugs.� Chris Stad don, University of Nottingham discussed X-ray studies of N doped GAAS as an application of the Mirror/Monochromator on the X'Pert MRD. These sessions were very useful for delegates considering the purchase of new instruments or upgrading existing instruments.

The XRD Plenary sessions included a presentation by John Faber, ICDD on "New Developments in Database Development and Data Mining". John reported that there are now 125,000 records in the ICDD databases and� in addition to patterns based on experimental data there are an increasing number of calculated patterns.� Relational Databases (RDB) are now being developed. PDF-4/Metals and Alloys were released in 2000, PDF-4/Minerals was released this summer and a full version will be released in 2002. These databases contain full patterns, which are a fingerprint of each compound. The databases also include crystallographic data from Cambridge Crystallographic Data Centre. John gave some examples of datamining using RDB's. On e example involved finding the distribution of crystal systems and space group populations. A search for Ln₂O₃ structures gives all structures, spaces groups and structure groups plus the stability of rare earth oxides. Steve Norval, ICI presented the second XRD plenary lecture "European Diffraction Standards-why should I care".� Steve discussed the problems associated with comparing data produced by different instruments. The European XRPD standards are designed to over come these problems. The five documents are "General Principles", "Procedures", "Instruments", "Terminology" and "Reference Material". Instruments could be most significant, providing a basis for specifying an instrument configuration, then following the alignment, calibration testing and monitoring sequence.

The XRD sessions included 3 "Practical Master Classes". The first covered "Sample Preparation and Spray Drying and was presented by Steve Norval, ICI and Steve Hillier, Macauley Land Use. The emphasis here was on the problems created by preferred orientation and how to remove it. Steve Norval discussed the results of a "Round Robin " which had been the basis for a workshop at� the BCA Spring Meeting at Heriot Watt University. He described the sample preparation options of side filling, front filling, back filling, a slurry on single Si crystal, spray drying and capillaries. The results of the Round Robin showed that spray drying was best with the use of capillaries nearly as good. Steve Hillier continued the session concentrating on the spray drying technique. In the past this method has required high cost equipment, gave poor product recovery, was time consuming and was unsuitable for small samples. New developments in the technique have made it relatively low cost. Using a modified airbrush to produce the spray it is possible to collect a product which consists of spheres which will produce random packing and reduce orientation.

John Faber, ICDD p resented the 2^nd master class on "Qualitative and Quantitative Analysis". John began with a brief history of powder diffraction databases and continued with a discussion of the use of Hanawalt and Fink Indexes to identify compounds and mixtures. This was followed by an overview of "Automatic Search Match" from first generation methods to the present day.� Finally John described the fourth generation search match programs with the emphasis on total pattern matching and the possibilities to include quantitative analysis.

Paul Fewster, Philips Analytical Research Centre and Dave Taylor, Consultant presented the third master class. The topic was "Calibration and Alignment" and David opened the session with a discussion on the UK Round Robin carried out by the Industrial Group, BCA� which� tested the performance of 30 diffractometers.� Details of the results, how to carry out the tests and how to obtain good XRD standards are on the IG pages of the BCA website. In the second half of the session Paul discussed diffractometer configuration and the different instrument settings such as slits and X-ray tube required to obtain high resolution or high intensity. This was followed by an overview of the basics of correct diffractometer alignment.

Other XRD sessions included "X-ray Scattering" which began with Paul Fewster, Philips Analytical Research Centre describing what happens from "source to detector". This included the assumptions made about dif fractometers and samples and therefore our interpretation of data obtained. Paul discussed the use of slits, mirrors and crystals,� factors affecting resolution. He covered the geometry of diffraction for single and polycrystalline materials, the effect of a diverging beam and spread of wavelength, the effect of focus size on peak intensity, wavelength selection and tuning the wavelength with the monochromator. Chris Hammond, University of Leeds followed with a presentation on "X-ray diffract ion from Multilayers and Single Crystal Thin films" which covered the ways in which multi-layers and single crystal thin films can be studied in the diffractometer. Peter Petrov, South Bank University, discussed the evaluation of residual stress in thin/thick films using grazing incidence diffraction. The examples he used to demonstrate the technique were SrTiO3 which has a cubic peroskovite structure and a superconductor� YBa₂Cu₃O_7-X.

A session on g eneral X-ray diffraction applications looked at a broad spectrum of techniques and applications. Marcus Neumann, Accelrys Ltd discussed structure solution from powder diffraction. Direct space methods used a combination of indexing, Pawley refinement, structure solution with RelfexPlus and Rietveld refinement. Structure solved included those for for Alfizosine (an alpha blocker) and tetracycline hydrochloride. Even moderate degrees of preferred orientation can prevent structure solving but th e determination of a preferred orientation correction factor has improved structure determination.

Richard Morris, Huntsman Surface Sciences, described how "Small Angle X-ray Scattering" (SAXS) can be used to measure the Bragg spacings of the lamellar phase in surfactants. These spacings increase in size with water content. This has lead to the development of continuous on-line measurement of the phase bound water content in concentrated surfactants.� Martin Gill, Imperial Co llege showed how clay minerals could be an indicator of climate change. Climate changes can lead to irreversible changes in clay structure.� XRD� determination of Hampshire Basin deposits have shown cyclical astronomical effects on the earth climate reflected in clay structure .

Patricia Kidd, Philips Analytical Research Centre, described the applications of in-plane scattering. The incident beam enters a sample at an angle close to zero and penetrates the sample surface down to a ma ximum depth of 100nm. The beam follows a path approximately parallel to the surface so that scattering occurs from crystal planes approximately perpendicular to the sample surface. Using this method lateral grain sizes or crystal homogeneity can be measured.

Judith Shackleton, University of Manchester Materials Science Centre, looked at XRD Stress Mapping of Inertial welds using a GADDS system. Inertial welding is carried out by slamming a spinning component into a stationary compone nt and allowing friction to form the weld. Analysis has been carried out on slices of weld areas using the GADDS system at Manchester. It is possible to see the weld with the video camera on the GADDS system and determine exactly where to carry out analysis.� Jodie Guest, University of Wolverhampton gave a practical evaluation of quantitative Rietveld Refinement of powder X-ray diffraction Data. The Rietveld� method offers advantages over conventional XRD methods and Jodie demonstrated the ca pabilities if the method for a range of samples.

Andeas Grimstvedt, Geological Survey of Norway discussed quantification of rock deposits with XRD based on Partial Least Squares (PLS) Regression. Calibration materials were obtained from mineral separation and then the separated minerals mixed in different weight proportions to give standards.� Generally calibration based on PLS gave better results than traditional methods. Colin Small, Rolls-Royce plc gave an overview of new geological problems for jet engines.� Item such as birds, spanners, volcanic ash or sand can be sucked into the engines causing damage. New problems associated with this include the cracking of corrosion and oxidation resistant alloys designed to operate at very high temperature. Colin described how XRD phase analysis lead to an understanding of the mechanism of the cracking and the design of a solution.

On the last day of the conference there was a joint XRD/XRF session on "The quality of the analytical result. The speakers for this session were David Dyson, who gave his personal view of the requirements (as set out in ISO 17025) for validation of methods and quality of results in relation to XRD/XRF.��� Elizabeth Pritchard, Laboratory of the Government Chemist, first discussed the aim of the Valid Analytical Measurement program (VAM), the six VAM principles and how they link into the requirements of ISO17025 . Elizabeth's second talk concerned measurement uncertainty a nd its estimation and gave an introduction to the ISO rules of calculation uncertainties.

Jo Jutson