In one of my refinement of Hydroxyapatite, I am getting blue colored circles for Ca1 and Ca2 and red for oxygen. I was able to address the oxygen but the hole issue with Ca1 and Ca 2 was not addressed, and hence my chi value was close 7.6 any suggestions as to what i should do ?
Could be a mismatch of the site occupancy factor. If your sample contains less electrons than a fully occupied Ca ion on the Ca sites, for example due to some Mg substitution, you can try the following: E=(CA(p), MG(1-p)) PARAM=p=1_0^1 x=... p refines the amount of Mg substituting Ca. In case there are more electrons than Ca, you can try the same with Sr instead of Mg.
I tried this too but i am getting an error. This is the error I got 1th pattern file named P027090051-01.xy: assuming free XY[E] format (E) wrong element identifier E=(CA(p), error detected in atomic position 1 error detected in phase 1 @@profextutorials2325
@saurabh khandelwal It depends on what your criteria for quality control are. If you are interested in phase purity, a structure refinement or electron density map isn't necessary. I think parameters such as phase purity, crystallite size, cell parameters, or a chemical analysis are easier to use for quality control. But your criteria might be different.
Than you for your tutorials they are amazing. I have a question since I'm not chemist but civil engineer, can I use this methods for analysis of cement based samples?
Sure, it is a common technique to quantify the phases in cement samples. However, I wouldn't attempt to do structure refinements of such samples (i.e. refine atomic coordinates or site occupancy factors) because the composition of Portland cement is relatively complex. But phase quantifications as shown in the "first refinement" and "case studies" videos work well for cement samples.
Thank you very much for the very useful content and nice explanation
It's my pleasure :)
how did you deduce there was strontium in HAp. You did not select Apatite-Sr for it.
It was a synthetic Sr-doped material. Otherwise I would have checked for impurities by XRF.
In one of my refinement of Hydroxyapatite, I am getting blue colored circles for Ca1 and Ca2 and red for oxygen. I was able to address the oxygen but the hole issue with Ca1 and Ca 2 was not addressed, and hence my chi value was close 7.6 any suggestions as to what i should do ?
Could be a mismatch of the site occupancy factor. If your sample contains less electrons than a fully occupied Ca ion on the Ca sites, for example due to some Mg substitution, you can try the following:
E=(CA(p), MG(1-p)) PARAM=p=1_0^1 x=...
p refines the amount of Mg substituting Ca. In case there are more electrons than Ca, you can try the same with Sr instead of Mg.
I tried this too but i am getting an error. This is the error I got 1th pattern file named P027090051-01.xy: assuming free XY[E] format
(E) wrong element identifier E=(CA(p),
error detected in atomic position 1
error detected in phase 1 @@profextutorials2325
You probably added a space after the comma (CA(p), MG(1-p)), that is not allowed. The space character must be removed: (CA(p),MG(1-p))
Very informative... thanks.
amazing video, can we use this method to compare the quality of the same material synthesized numerous times?
@saurabh khandelwal It depends on what your criteria for quality control are. If you are interested in phase purity, a structure refinement or electron density map isn't necessary. I think parameters such as phase purity, crystallite size, cell parameters, or a chemical analysis are easier to use for quality control. But your criteria might be different.
Than you for your tutorials they are amazing.
I have a question since I'm not chemist but civil engineer, can I use this methods for analysis of cement based samples?
Sure, it is a common technique to quantify the phases in cement samples. However, I wouldn't attempt to do structure refinements of such samples (i.e. refine atomic coordinates or site occupancy factors) because the composition of Portland cement is relatively complex. But phase quantifications as shown in the "first refinement" and "case studies" videos work well for cement samples.
@@profextutorials2325 Ok, thank you very much !☺
hello, at 18:34, are you saying 'site of cubancy factor' ? thanks
That should be "site occupancy factor" ;)
@@profextutorials2325 wow thanks for the quick reply