At 05:33 PM 7/22/98 +0000, Chuck wrote:
>Another question from a confused novice:
>
>I'm trying to refine a LaB6 XRD pattern to get my instrument function.
>Right now I'm using FullProf. The problem I have is that the calculated
>intensity for the low angle peak, (100) at 24.87° for Co Ka rad., is way
>too big (100%). So that throws off all my intensities (which I imagine are
>also not correct) and I can't get reasonable R's. This happens whether I
>use an Inel CPS-120 or a Siemens D500.
>
>Is this a result of micro-absorption and can I correct for it using the
>Brindley correction? I've found a few articles using this (just ordered
>them), by Taylor, JC, et al. and Collazo J, et al. Are there any others
>that would help to understand this phenomenon?
>
>
LaB6 (SRM 660) orients preferentially in the 100 direction. Try a
preferred orientation correction. Microabsorption (Brindley) is operative
only in multiphase systems.
Jim
James P. Cline Cline@Credit.NIST.gov
Ceramics Division Voice (301) 975 5793
A256/223 FAX (301) 975 5334
National Institute of Standards and Technology
Gaithersburg, MD 20899 USA