Does metal organic frameworks (MOFs) crystallinity calculation need to a standard sample?
You can always calculate the ideal pattern from a structure file. When it comes to porous MOFs, the peak intensity is heavily influenced by pore occupying solvents and water.
I'm not sure if I understand what you need, though. There are a lot of published patterns of HKUST-1, and the structure is also available. You could use PXRD software such as Topas, Reflex or Expo to refine the structure against your data.
If you're looking for the degree of crystallinity in your sample; high relative signal to noise ratio, low FWHM values and diffraction to higher angles are good indicators.
You can always calculate the ideal pattern from a structure file. When it comes to porous MOFs, the peak intensity is heavily influenced by pore occupying solvents and water.
I'm not sure if I understand what you need, though. There are a lot of published patterns of HKUST-1, and the structure is also available. You could use PXRD software such as Topas, Reflex or Expo to refine the structure against your data.
If you're looking for the degree of crystallinity in your sample; high relative signal to noise ratio, low FWHM values and diffraction to higher angles are good indicators.
Are to trying to determine the percentage of the sample that is crystalline and the percentage that is amorphous? That can be done. You don't need a standard as long as you know the crystal structure is known so you can calculate the structure factors. Have you already made a measurement? If so attaching a plot would be very helpful.
Please tell a little bit more detailed about your intention. Do you want to determine
- The amount of crystalline and amourphous fraction? This is not as easy as LM want to tell! But different methods for determination of the quantity of an amourphous phase exist.
- The crystallite size and strain within the crystalline fraction?
- The quality of the ordering of the atomic positions?
- If the material is not stored under inert conditions then also water or other molecules may fill the cavities, as SO noted. Do you want to determine the quantity and type of absorbed matter?
If you maintain a constant diffracting volume, relative analyses are straightforward. You'd need some "known standards" to quantify better, I'd think.
What is the end use for this material in your case? Post a typical XRD profile when convenient.
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