X-ray Methods Subcommittee Agenda and Minutes

X-ray Methods Subcommittee
29 July 2001
Chairman - Scott Misture

1. Attendance sheet is on file at Headquarters.

2. Approval of Minutes of the March 2001 meeting - There were no corrections to the minutes, and they were accepted by the membership.

3. Old Business

A. X-ray Optics Task Group Activities

Scott Misture, Task Group Chair, presented the results of a mini-round robin conducted among 5 laboratories. The purpose of the review was to determine if a full round robin might be necessary to evaluate data obtained using instruments with parallel beam optics. The summary results showed that the lattice parameters obtained were in agreement with the certified values for SRM1976 only after application of a goniometer zero shift correction. The intensities were even worse, with none of the laboratories within the error values suggested by the National Institute of Standards and Technology (NIST). However, it is interesting to note that the line shape vs. angle was reasonable and that Rietveld refinement of some of the data provided the certified values for the lattice parameters without difficulty.

The Subcommittee suggested that the motion brought to the Board of Directors in March 2001 should be tabled. (The motion requested a full evaluation of the data using NBS*AIDS by the ICDD staff). Instead, the Task Group leader volunteered to make the data available on the ICDD website for review and additional discussion before the March 2002 meeting.

B. X-ray Reflectivity (XRR)

The Task Group chair was not present, but it was agreed that the original meeting of the Task Group in Denver 2000 was effective in getting some of the manufacturers to discuss the needs for calibration standards for XRR directly with NIST. Additional Task Group activities remain unclear - the original intent was to provide an XRR instrument use/alignment guide for the inclusion in the Methods and Practices Manual. Although this might still be possible, the rather more important task of starting a discussion of standards was achieved.

C. High Temperature XRD

The Subcommittee agreed that this possible Task Group should reside in the High Pressure Subcommittee. Members present and interested in the topic were made known.

4. New Business

A. X-ray Optics

The Subcommittee and Task Group Chair, Scott Misture, had several meetings with some of the major instrument manufacturers in a role as the ICDD Subcommittee Chair. The meetings occurred at the 2001 Denver X-ray Conference (DXC) and were only preliminary before the Subcommittee meeting. The meetings focused on the possible formation of a new subcommittee, perhaps as a Task Group under X-ray Methods, that includes a major effort to educate the user community on new x-ray optics (multilayer, capillary, etc. - not including crystal optics).

5. Update from the Board of Directors: no update

6. Adjournment.