RE: x-pert pro from philips

[Van den Berghe Sven]

We have been using the X'Pert Pro diffractometer for about a year now.  We haven't done many refinements yet, but from those that were done, we have reached some conclusions.  The X'Pert Pro is very well suited for refinement work, but its high resolution poses some problems.  Strange, isn't it ?  As diffractometers have become better and better, inherent errors have become more and more visible and more and more annoying for refinements.  The main error is the axial divergence that produces peak asymmetry at low diffraction angles.  We have found that 0.02 rad Soller slits are required to produce good spectra that can be modelled with the known, regular peak functions.  For other Soller slits, one would have to resort to correction functions, such as the one included in FullProf (don't remember the name, but it's described with a reference in the manual). If you are worried about the click-on or PreFix system : we haven't found any alignment problems with this system.  Although we now regularly change the setup and even the tube focus from line to point, the alignment stays within acceptable limits.  For the top class work, one should always align the goniometer before starting an experiment anyway...   I'll be happy to answer any specific questions you may have...   Sven Van den Berghe   **************************************************************** Sven Van den Berghe Scientific Researcher Reactor Materials Research Department (RMO) Laboratory for High and Medium Activity (LHMA) Boeretang 200 B-2400 Mol Belgium Tel. : +32 14 33 30 64 Fax : +32 14 32 12 16 E-mail : [EMAIL PROTECTED] ****************************************************************   -----Original Message----- From: sasaki [mailto:[EMAIL PROTECTED]] Sent: Thursday 26 April 2001 12:33 To: RIETVELD_L Distribution List Subject: x-pert pro from philips Dear all Rietvelders     I would appreciate to receive address of who are operating the new generation of Philips diffractometer called X-pert Pro and what is the reliability of this equipment concerning the Rietveld refinement for powder samples.    Thanks in advance     Sasaki   ********************************************** Dr. Jos� Marcos Sasaki Universidade Federal do Cear� - UFC Departamento de F�sica Laborat�rio de Raios-X Campus do Pici Caixa Postal 6030 60455-760 Fortaleza - CE - Brazil Phone: +55(85)288-9917 Fax: +55(85)288-9903 E-Mail: [EMAIL PROTECTED] http://www.fisica.ufc.br/raiosx/LBRX.html ***************************************************