I have access to a Panalytical MPD materials Research diffractometer with a scintillation detector, a Euler cradle and divergent optics in the incident path, but I need help with the way to perform the analysis, how to position the sample height, how to optimize the difference angles, Phi, Psi...
Yes, it is possible to use detectors ranging from 0D point counters to 1D linear position sensitive detectors to the good old photographic film (an extinct species in the XRD lab these days) to modern "Back to the Future" 2D detectors. Depends on how motivated and open minded one is.
No matter what tools you use, in simple English, the basics ("protocol") are still the same.
1. Find the diffractometer axis (z-axis) and make sure it is normal to the diffractometer "equatorial plane". Basic!
2. Make sure the incident beam is parallel (if line source) to the diffractometer axis and the axis bisects the incident beam (hopefully rectangular or near so).
3. Position the sample surface parallel and collinear to the diffractometer axis. Adjust Omega (0 deg.), Phi, Chi/Psi to observe both incident beam and the XRR beam (Two beams! "Split beam"!).
https://www.flickr.com/photos/85210325@N04/15563390403/
4. Perform 2Theta-Omega scan while recording the data in 2D.
See images attached. Using a conventional 0D scintillation/point detector for this task is tantamount to "walking in a busy shopping mall with a blindfold and handicapped with only a pinhole to look through". You could do it, slowly & carefully. Others do so even now (for the past century) on a daily basis. However, I suggest using a combo of 0D counter and film (commandeer it from a local "old time" dentist) in order to optimize the sample for the maximum signal to noise ratio. Then take the final quantitative observation with the 0D, that you certainly have, using the smallest of slits possible. Good luck!
A Better, Faster, Smarter, Modern Way! Here's the "lead horse view" using a real time 2D Bragg XRD Microscope attachment (cost effective, state-of-the-art US technology) mounted on a Bruker or Panalytical Diffractometer (or other). It took us about 5 minutes including alignment to acquire 5000+ 800x800 pixels frames. Spatial resolution 29um. Angular (reciprocal space) resolution 0.75 Arcsec. SDD - Sample to detector distance of 145 mm. The 3D data volume nearly 3GB. Using the conventional tools you'll turn into a Rip Van Winkle duplicating these results :-)
(https://www.flickr.com/photos/85210325@N04/11343736043/in/set-72157645018820696)
I think there are separate detector for thin film, So you have to replace it with the detector used for powder sample.
Yes, it is possible to use detectors ranging from 0D point counters to 1D linear position sensitive detectors to the good old photographic film (an extinct species in the XRD lab these days) to modern "Back to the Future" 2D detectors. Depends on how motivated and open minded one is.
No matter what tools you use, in simple English, the basics ("protocol") are still the same.
1. Find the diffractometer axis (z-axis) and make sure it is normal to the diffractometer "equatorial plane". Basic!
2. Make sure the incident beam is parallel (if line source) to the diffractometer axis and the axis bisects the incident beam (hopefully rectangular or near so).
3. Position the sample surface parallel and collinear to the diffractometer axis. Adjust Omega (0 deg.), Phi, Chi/Psi to observe both incident beam and the XRR beam (Two beams! "Split beam"!).
https://www.flickr.com/photos/85210325@N04/15563390403/
4. Perform 2Theta-Omega scan while recording the data in 2D.
See images attached. Using a conventional 0D scintillation/point detector for this task is tantamount to "walking in a busy shopping mall with a blindfold and handicapped with only a pinhole to look through". You could do it, slowly & carefully. Others do so even now (for the past century) on a daily basis. However, I suggest using a combo of 0D counter and film (commandeer it from a local "old time" dentist) in order to optimize the sample for the maximum signal to noise ratio. Then take the final quantitative observation with the 0D, that you certainly have, using the smallest of slits possible. Good luck!
A Better, Faster, Smarter, Modern Way! Here's the "lead horse view" using a real time 2D Bragg XRD Microscope attachment (cost effective, state-of-the-art US technology) mounted on a Bruker or Panalytical Diffractometer (or other). It took us about 5 minutes including alignment to acquire 5000+ 800x800 pixels frames. Spatial resolution 29um. Angular (reciprocal space) resolution 0.75 Arcsec. SDD - Sample to detector distance of 145 mm. The 3D data volume nearly 3GB. Using the conventional tools you'll turn into a Rip Van Winkle duplicating these results :-)
(https://www.flickr.com/photos/85210325@N04/11343736043/in/set-72157645018820696)
Ravi is entirely correct. I used to perform this exact experiment with a Rigaku Ultima IV, a Euler cradle, and a powder detector. The only thing that I have to add is that since detected X-ray intensity drops off so quickly, you will have to set a program to change slits/attenuaters either on-the-fly or perform the experiment in stages. Panalytical also has an approximately 45 minute webinar that you should be able to access on this subject (http://www.panalytical.com/Event/XRay-Reflectivity-and-Thin-Film-Research.htm). I also know that my sales-person/contact was very happy to provide step-by-step protocols when asked.
Thanks very much Ravi and Robert for your helpful information, I'll try to get some more information from my local sales person.
Thanks again.
Yes, I would be very thankful if you can provide the protocol.
Thanks Ravi.
Cristóbal! What thin films are you working with? What growth technique? What Nano structural parameter are you looking to measure using XRD?
Post some related work in literature if available and when convenient. You'll get better responses from RG membership when you state your objectives clearly and provide sufficient background information.
I'm working on deposition of apatites on mica substrates by vapour diffussion, we need to identify the deposited phase and if possible to measure the thickness of the deposited apatite film.
Is the mica substrate "optically flat"?
Are you familiar with XRR?
Can you send me a sample film/substrate to test feasibility?
What is the end-use of such thin films?
Please post some literature references for this type of research when convenient.
I got some of my old data out of storage this weekend. I will try and find a good experimental in one of these hard drives and post a rough procedure
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