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| xrd:start [2013/05/01 22:51] – janet | xrd:start [2020/03/06 09:04] (current) – external edit 127.0.0.1 |
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| ====== X-Ray diffraction ====== | ====== X-Ray diffraction ====== |
| In order to do XRD, you need to go to radiation safety training ([[http://oregonstate.edu/ehs/rso/x-ray#xray1|information here]]) and arrange for machine-specific training. | In order to do XRD, you need to (i) go to radiation safety training ([[http://oregonstate.edu/ehs/rso/x-ray#xray1|information here]]) and (ii) arrange for machine-specific training. |
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| Scheduling of the equipment is via the online scheduler at this page (as of 2013-05-01): [[http://www.science.oregonstate.edu/~kykynesr/|http://www.science.oregonstate.edu/~kykynesr/]] | Scheduling of the XRD equipment in Gilbert Hall is via this online scheduler at this page (as of 2013-05-01): [[http://www.science.oregonstate.edu/~kykynesr/|http://www.science.oregonstate.edu/~kykynesr/]] |
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| ===== Equipment ===== | ===== Equipment ===== |
| Bruker D8 Discover - Dearborn 201- Mostly used for thin films, although you can also put powders in it. Can be used to do phi scans, chi scans, rocking curve measurements, xrr, etc (these require special training because you have to use the scintillator, which isn't normally installed). Be sure to use the "snout" on the x-ray source, otherwise you end up with a broad background radiation signal. | Bruker D8 Discover - Dearborn 201- Mostly used for thin films, although you can also put powders in it. Can be used to do phi scans, chi scans, rocking curve measurements, xrr, etc (these require special training because you have to use the scintillator, which isn't normally installed). Be sure to use the "snout" on the x-ray source, otherwise you end up with a broad background radiation signal. |
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| Rigaku Ultima - Gilbert 020 - | Rigaku Ultima IV multipurpose X-ray diffraction system - Gilbert 020 - also XRR |
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| Rigaku Miniflex Xray Diffractometer - Gilbert FIXME room # - Useful mostly for powders. The x-ray beam is too weak for much thin film work, though it may be usable if you have strong peaks (e.g. from epitaxial films). | Rigaku Miniflex Xray Diffractometer - Gilbert FIXME room # - Useful mostly for powders. The x-ray beam is too weak for much thin film work, though it may be usable if you have strong peaks (e.g. from epitaxial films). |
| * Powder Diffraction Files (JCPDS from ICDD). Access to this resource in the Valley Library is on the middle PC on the long portion of the the “L” shaped desk behind the "Ask Here" desk on the first floor. The machine is marked "Powder Diffraction". Login with ONID ID and find the PDF icon on the desktop. Software is easy to use. Take a USB drive to print PDF files to it. | * Powder Diffraction Files (JCPDS from ICDD). Access to this resource in the Valley Library is on the middle PC on the long portion of the the “L” shaped desk behind the "Ask Here" desk on the first floor. The machine is marked "Powder Diffraction". Login with ONID ID and find the PDF icon on the desktop. Software is easy to use. Take a USB drive to print PDF files to it. |
| ===== Tutorials ===== | ===== Tutorials ===== |
| * A good XRD [[http://prism.mit.edu/xray/Introduction%20to%20XRPD%20Data%20Analysis.pdf|starter tutorial from MIT]]. | There is a good set of tutorials at MIT: |
| | * [[http://prism.mit.edu/xray/oldsite/1%20Basics%20of%20X-Ray%20Powder%20Diffraction.pdf|Basic XRD tutorial]] (Speakman, MIT) |
| | * [[http://prism.mit.edu/xray/Introduction%20to%20XRPD%20Data%20Analysis.pdf|Powder XRD data analysis tutorial]](Speakman, MIT) |
| | * [[http://prism.mit.edu/xray/oldsite/Introduction%20to%20HRXRD.pdf|Thin film XRD tutorial]] (Speakman, MIT) |
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| ===== X-Ray Techniques ===== | ===== X-Ray Techniques ===== |
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| If your film is strongly oriented, you can get the other parameters by rotating in χ. E.g. if you have a (001) film, you can get //a// and //b// by looking at (h0l) and (0kl) peaks. These lattice parameters will be determined less accurately - the signal is small and any error in //c// will propagate into //a// and //b//. | If your film is strongly oriented, you can get the other parameters by rotating in χ. E.g. if you have a (001) film, you can get //a// and //b// by looking at (h0l) and (0kl) peaks. These lattice parameters will be determined less accurately - the signal is small and any error in //c// will propagate into //a// and //b//. |
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| | ==== X-ray Reflectivity or Reflectometry (XRR) ==== |
| | Can get thin film thickness by modelling fringes (XRay refractive index very close to 1, so no problems with knowing index as in optical measurements). Critical angle for Total External Reflection gives density of film (XRay refractive index in a material is slightly less than 1, so the familiar optical "TIR" becomes external refleciton). Surface roughness can be measured. Some modelling required. |
