Hello,

Similar questions have been discussed here many times. But I would mention here that "the conclusion was that the shift reveals the crystallization process and the quality of the grown separate crystals" is incorrect. The point is that the positions of the diffraction lines themselves are, according to Bragg's law, a function of the interlayer distances. The interlayer distances themselves are a function of the unit cell parameters and, of course, the actual space groups. The shift of the diffraction lines from the standard position therefore corresponds to a change in the size of the unit cell, which is usually a function of doping. For phases containing multiple structural positions for doping, the effect of doping on cell parameters may be more complex. Shifts can easily be on either side.

The quality of crystallization, ie the size of the coherent diffraction domains or ie the size of the crystallites is reflected in the widths of the diffraction lines (FWHM, full with at half maximum ).

Dear Dattatray Gadkari

Hope you look at the following RG links. its contains a bundle of knowledge related to your query.

Best regards...

https://www.researchgate.net/post/What_is_the_reason_of_peak_shifting_in_XRD_towards_higher_angle_side_after_the_sample_has_been_irradiated

https://www.researchgate.net/post/What-are-all-possible-reasons-for-the-peak-shift-in-X-Ray-Diffraction

https://www.researchgate.net/post/When-XRD-analyzed-what-does-it-mean-when-a-shifted-peak-is-either-left-hand-or-right-hand

Dear Mohammed Hussein j. H. Al'Atia

Opened the links given in your answer, it seems that the answers are routine. Expectation for the detached single crystal is that how the interface shape and crystalline quality might be influenced (affected) by these shifts.

We have grown 72 detached Sb-based crystals in our laboratory. Thus conclusion is based measurement results on the crystal growth experiments by VDS-Process. However, observed shifts have been influenced the measured properties of the detached crystals. As there are report about the variation of interface shape for the detached crystal grown in space but no report for the detached crystal grown on Earth.

Dear Dalibor Matýsek,

The mentioning is that the conclusion sentence into explanation of the question is incorrect.

The conclusion was based on VDS-Process experimental measurements for the seventy two detached single crystals growths.

For example, the measurements of as grown detached crystals showed: I) Hall mobility of the doped crystals increased w.r.t. the undoped crystals, II) FWHM decreased w.r.t. the undoped crystals III) Interspacing distance reveals the decreased in some crystals and other crystals increased w.r.t. the undoped crystals etc.

Overall physical parameters analysis had been based on detached crystal and influence on increased crystallinity.

Therefore, the research study showed variation which was related to the conversion process of detached crystals from melt to solid (crystallinity) and also which could be the interface shape effect. The detailed analysis was reported in RG.

Dear Dattatray Gadkari

Thank you for your kindly feedback. In [1] and [2], I have read two of your recent publications that highly related to the topic of your query. In this respect, you did more than well to push for more success and higher research quality. Now, I can say that you may need to have 2D thermal analysis across the section of ampoule at the two phases of the alloy and the melt-solid interface since the momentum of heat and mass transfer in this section may produce a non uniform boundaries leading to unsteady state crystallization process.

Best regards

[1]Article Relation of Heat Transfer with the Growth Rate of InSb based...

[2]Article The homogeneous and entire detached In 0.5 Ga 0.5 Sb alloy c...

Dear Mohammed Hussein j. H. Al'Atia,

Thanks for reading and reference of VDS publications. The research interest has been concentrated on the analysis of interface shape and crystallization and its influence on crystallinity.

Dear Mohammed Hussein j. H. Al'Atia,

Addition to earlier reply, you are requested to read the below articles ---

[1] file:///C:/Users/GADKARI/AppData/Local/Temp/G1010023551.pdf

[2] file:///C:/Users/GADKARI/AppData/Local/Temp/B1009040519.pdf

Changes in the unit cell due to substitution of other impurities or due to stress are the two mechanisms responsible for shifting of the XRD peaks.

Because of the size of crystal, the diffraction peaks shift to the left or right in XRD diffraction patterns. When the crystal size is small, the diffraction patterns shift to a higher diffraction angle, but when the crystal size is greater, the peak shifts to a lower diffraction angle.

1. R.Sagayaraj, S.Aravazhi, C.Selva kumar, S.Senthil kumar, & G.Chandrasekaran, Tuning of ferrites (CoxFe3-xO4) nanoparticles by co-precipitation technique, SN Appl. Sci. 1(3) (2019) 271

2. R.Sagayaraj, M.Jegadheeswari, S.Aravazhi, G.Chandrasekaran, & A.Dhanalakshmi, Structural, Spectroscopic and Magnetic Study of Nanocrystalline Terbium–Nickel Ferrite by Oxalate Co-Precipitation Method. Chemistry Africa 3 (2020) 955-963

3. R.Sagayaraj, T.Dhineshkumar, A.Prakash, S.Aravazhi, G.Chandrasekaran, D.Jayarajan, & S.Sebastian, Fabrication, Microstructure, Morphological and Magnetic Properties of W-type ferrite by Co-precipitation method: Antibacterial activity. Chem. Phys. Lett 759 (2020) 137944.

4. R.Sagayaraj, S.Aravazhi, G.Chandrasekaran, Effect of Zinc Content on Structural, Functional, Morphological, Resonance, Thermal and Magnetic Properties of Co1−xZnxFe2O4/PVP Nanocomposites. J Inorg Organomet Polym Mater.29(2019) 2252–2261.

5. R.Sagayaraj, S.Aravazhi, G.Chandrasekaran, Microstructure and magnetic properties of Cu0.5Co0.3Mo0.2Fe2O4 ferrite nanoparticles synthesized by Coprecipitation method. Appl. Phys. A 127(7), (2021)502. https://doi.org/10.1007/s00339-021-04653-z

6. R.Sagayaraj, S.Aravazhi, G.Chandrasekaran, Review on structural and magnetic properties of (Co–Zn) ferrite nanoparticles. Int Nano Lett 11(4) (2021) 307-319. https://doi.org/10.1007/s40089-021-00343-z.

While applying hydrostatic pressure the peaks have to shift to the right and while releasing the pressure the peak will again shift to the right that also before any phase transition. Or while heating also lattice may expand otherwise on compression or expansion by externally also the peaks may shift right and left.