There is a difference between experimental and simulated Powder X-ray diffraction peak heights for our transition metal complexes. Could anyone give us a reason.
Simulated powder x-ray diffraction analysis made by the program is considered to be pure and clean material. However, your experimental work may also contain impurities in the material. So there may be differences between the two graphics
The positions of the peak match, so there is no impurities. Only the peak heights differ.
339/5000
Peak heights vary depending on the material concentrations that the material contains. Already simulated powder x-ray diffraction is very difficult trying to find the same magnitude of the experimental work.
Dear Adnan,
peak widths and thus peak heights are very sensitive to crystallite size (and strain/stress).
So if you don't model these parameters according to your sample you will fail in peak height prediction.
So please use the peak integrals for comparing your data. Peak integrals are much less sensitive to the above mentioned parameters.
Please have a look at the links for size and strain broadening.
Orientational artifacts often show up in XRD pattern. Even for powder samples you may suffer from it due to too large particles. In this case there are not enough particles in the x-ray interaction volume of your system in order to have a sufficient homogenouos orientational distibution of the crystallite directions.
Please mill your sample again (to a fine powder) and repeate your measurements.
https://en.wikipedia.org/wiki/Scherrer_equation
https://en.wikipedia.org/wiki/Powder_diffraction
Hi Adnan
Have you refined occupancy?
The intensity of diffracted beam in a particular direction is proportional to the modulus of square of geometrical structure factor (Fhkl), which depends on the occupancy of atoms in different Wyckoff positions of a unit cell.
Can you post your graph?
It sounds like you are not trying to do a Rietveld refinement on your data. Which means many things could be wrong with your simulation, like crystal size and strain/stress. The peak positions match does not mean your material is pure, it only means the structure model you used has the same lattice parameter as your material. The intensities of the peaks depends on the exact crystal structure of the material, what are the atom positions in the unit cell, what kind of atoms are there. if the simulated result doesn't match your experiment, that means your structure model is probably inaccurate.
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science