No, you are not provocative Alan. You are right. I have reacted only to the X-ray discussion (no neutrons in the labs). It is a pity that the procedure for getting the beamtime at the synchrotron and neutron sources is still so time-consuming. At least at the synchrotron, there is an activity to introduce or improve already existing mail-in system. I have a feeling that there is enough synchrotron beamtime for everybody to collect standard powder patterns. 20-60 sec / pattern with 2D detector + few min. for sample mounting is not so much. Who has analyzed powder patterns from synchrotron will never come back to the lab (this is provocative 🙂)
Radovan Radovan Cerny DQMP Université de Genève 24, quai Ernest-Ansermet CH-1211 Geneva 4, Switzerland mailto : radovan.ce...@unige.ch<mailto:radovan.ce...@unige.ch> URL : http://www.unige.ch/sciences/crystal/cerny/rcerny.htm ________________________________ De : rietveld_l-requ...@ill.fr <rietveld_l-requ...@ill.fr> de la part de Alan W Hewat <alan.he...@neutronoptics.com> Envoyé : mercredi 6 septembre 2023 11:17 À : Le Bail Armel <le-bail.ar...@orange.fr> Cc : Rietveld_L <Rietveld_L@ill.fr> Objet : [EXTERNAL] Re: Step-like basline "The biggest improvement was synchrotron radiation". No. The biggest improvement for the profile refinement of atomic and magnetic structures (Rietveld refinement in the strict sense) was high resolution neutron powder diffractometers with large area detectors :-) Even SR gives undue weight to heavy atoms, can suffer from systematic errors due to small samples, and of course is "not ideal" for magnetism, important for the properties of many materials. SR has some advantages to counter these disadvantages, but not for most new materials. Lab x-rays can do some structural work, but have most application for materials characterisation by multi-component profile refinement, when you need a result now, and not in 6 months time. But Radovan, is just being provocative (like me). Alan ________________________________ Dr Alan Hewat, NeutronOptics Grenoble, FRANCE (from phone) alan.he...@neutronoptics.com +33.476984168 VAT:FR79499450856 http://NeutronOptics.com/hewat _______________________________ On Wed, 6 Sept 2023, 10:48 Le Bail Armel, <le-bail.ar...@orange.fr<mailto:le-bail.ar...@orange.fr>> wrote: Hi, In the same subject. A special "powder pattern" to play with (try to explain all peaks) : http://cristal.org/muscovite.pdf Best Armel ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Please do NOT attach files to the whole list <alan.he...@neutronoptics.com> Send commands to <lists...@ill.fr<mailto:lists...@ill.fr>> eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Please do NOT attach files to the whole list <alan.he...@neutronoptics.com> Send commands to <lists...@ill.fr> eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
