Dear colleagues
We have growth ZnO microstructure on p type Si (001) substrates by Chemical Bath Deposition technique. For preparing the solution, Zinc acetate dehydrate (Zn(CH3CO2).2H2O) was dissolved in deionized water . Then 1 mL of ammonium hydroxide (NH4OH) was added to this solution and stirred at 87C.
See attached file for SEM image of the microstructure obtained.
XRD measurement is performed for this sample and compared to powder ZnO (Attached file).
As we can see in XRD spectrum a small shift of ZnO microstructure is observed compared to powder peaks for 2theta less than 60 deg, but this shift is more important (heigher than 1.2 deg for peaks in range 60deg
If you can make sure that there is no experimental error, the angle shift would be directly related to the interlayer distance d (d-spacing) as given by Bragg's equation: (2dSin(theta)=n(lambda).
The shifts to the left (lower angle) may be due to a small increase in the d-spacings.
Also keep in mind that usually powder samples have quite bit of different properties than samples grown directly on the substrate. Especially when it comes to particles size and particles orientation.
It is quite normal that small shifts at low angles to increase at larger angles. As the lattice parameter(s) (constant) are related to the d-spacing, and since d-spacings get smaller with increasing 2 theta, the shift gets larger. I guess, simply, that the lattice parameter for your sample is different from that you compare with.
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