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

 

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