Dear Md. Tanvir Hossain,
You may want to look at the data presented below:
It may be also the case for the small crystalline size specimens where the first subsidiary maximum may become important in the presence of the main maximum in the structure factor associated with the intensity of the scattering X-ray beams. This might cause some apparent displacements in the peak positions in the observed XRD spectrum (See: M.M. Woolfson), which may be lifted by the proper numerical analysis. ... The orientation had nothing to do with peak shifting. ... Preferred orientation in Powder XRD didn’t affect the peak position but the intensity of the particular plane i.e ... That means if one makes an XRD measurement on the as-received sample having textures without exposed to any...
https://www.researchgate.net/post/What-is-the-Preferred-Orientation-role-in-peaks-shifting-in-the-XRD
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https://msestudent.com/what-are-crystals-and-grains/
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Powder diffraction assumes a random orientation of the particles in the sample. If this is not the case and some orientation is preferred, this will necessarily be reflected in the intensities of the diffraction lines.
And yes, the preferred orientation can completely remove or significantly modify the diffraction pattern. It's easy to see for yourself. It is enough to measure the scale of mica, for example phlogopite, directly on the cleavage surface. Only the (00l) lines will be present in the diffraction pattern, nothing more.
Hi,
It can relate to the studied powder. If its growth is preferred in certain directions, it is more intense and dense. This necessarily leads to a significant impact on the severity of the diffraction lines (In this case, the peaks may not appear if they have a weak intensity in the first place).
Try to record a 2D XRD image and convert into 1D data. In the 2D data itself you can directly find the preferentially oriented peak, While converting to 1D choose chose the portion where there is no preferential orientation then you will get all the peaks uniformly.
Md. Tanvir Hossain
the very simple reason is that X-rays cannot 'see' all the diffracting planes when you have a prefferred orientation.
In powder diffraction, you use a powder sample in order to have a random distribution of particles and hence of orientation. In the case of preferred orientation you typically have planar particles that will all assume the same configuration above the sample holder. As a consequence you loose the random distribution of orientations; all particles will be distributed with about the same (preferred) orientation.
Finally, please avoid terms such as "Diffraction Spectra". A spectrum is obtained when you have an energy dispersion, that is generated by an anelastic interaction (between X-ray and your sample). Diffraction is an elastic phenomenon, so you obtain a pattern.
Md. Tanvir Hossain: In powder, XRD X-ray will see all the planes and in the case of the preferred oriented plane act almost like a single crystal hence it will diffract more than the other planes in the powder sample. I agree it is not diffraction spectra rather it is an XRD Pattern. Diffraction is not because of the elastic phenomenon but due to interference specular reflection of X-ray from different planes in the samples. @almo If you are not confident do not mis guide.
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