Hi Wing, I purchased LaB6 from http://www.thegemdugout.com/ for a fraction of price NIST charges and the same quality.
Peter Zavalij X-ray Crystallographic Center University of Maryland College Park, MD 20742 Phone: 301-405-1861 From: Julian Tolchard [mailto:tolch...@material.ntnu.no] Sent: Friday, February 19, 2010 1:27 AM To: Rietveld_l@ill.fr Subject: RE: Intrumental broadening of 2D detector Wing, This is something which has also been playing on my mind recently - you are not alone. I don't believe NIST has made LaB6 for a long time. I could use some more to supplement my dwindling supply, so I bought some LaB6 from Aldrich with a view to processing and annealing it, but I can't find any details about the temperature, atmosphere and cooling rates for the annealing of SRM 660. The certificate only says that it was annealed. I wonder if someone here knows more details. I remember there was some suggestion that Indium Oxide would also make a good standard material for this. jools _____ From: Wing Fai Lai [mailto:wfla...@yahoo.com] Sent: 19 February 2010 01:50 To: Rietveld_l@ill.fr Subject: Intrumental broadening of 2D detector Dear list members, I'm a beginner in XRD and now trying to estimate the instrumental broadening. My final goal is to measure crystallite size and microstrain of minerals. The equipment I've is Bruker D8 discover with GADDS(2D detector) and XYZ stage. I know this is not a setup for high resolution diffractometry but that's what I have in my lab. I'm unable to get NIST 660 because they have been out of stock for a few months. I've NIST 640d, is it good enough for estimating instrumental broadening or I should prepare LaB6 from heating LaB6(from Sigma) over 300C? Otherwise, do anybody know where can I get 660? My current setup is: 45kV, 45mA, copper anode, graphite monchromator, 30cm detector distance, theta1,theta2 starting at 8 degree, both move at 0.5 step size, to 45degree ,collection time=300s, 0.05mm monocap. After merging the frames, I just integrate the middle part of frames. Is this setup okay or what should be improved? Thanks a lot. Regards, wing fai
