we do not observe any Ag doping element in TiO2 XRD peak?
Md Mahamud Hasan Tusher Not enough concentration to provide a separate phase or distortion of the lattice. Perhaps (but unlikely) peak interference. What is your doping concentration?
Md Mahamud Hasan Tusher This is probably due to their low amount or their high dispersion in the samples with small dimensions below the detection limits of XRD
Hii,
You have not doped enough amount of Ag in TiO2. Try to do peak shift analysis of strong peak with respect to doping concentration. Try this
@Md Mahamud Hasan Tusher if you keep Ag in its metallic form or at its zero valence state, obviously it's not forming bond with TiO2. So there will not be bond formation of Ag in the unit cell of TiO2. So there shouldn't be any expectations of change in XRD peaks. Once Ag is oxidized to Ag2O and getting bonded with TiO2 through oxygen bridge, it's no longer Ag doping. If you really want to trace trapped Ag in the matrix of TiO2, select a 2theta value of stand alone Ag XRD peak that doesn't have any overlapping with any of the TiO2 XRD peaks and run a very slow scan for that 2 theta value.
Hii Md Mahamud Hasan Tusher ,
The X-ray diffraction patterns are obtained from the diffracted x-rays from the crystalline planes. Therefore, depends on the atomic positions and the interatomic as well as interplanar spacing. Assuming that you have doped Ag in TiO2 in a small fraction (may be < 10%), Ag will substitute Ti in TiO2 matrix.
So, Ag cations are substituted in TiO2 in place of Ti cations, which means the crystal structure does not change and hence will not change the diffraction patterns.
If the concentration of Ag increases and becomes greater than the saturation limit, then separate peaks corresponding to Ag can be observed as described by Alan F Rawle.
Said that, the ionic radii and size of Ag cations may be slightly different than Ti cations. Therefore, a small shifting in the peak positions (2theta values), intensity and FWHM may be observed as a consequence of doping.
It depends on the concentration of the doping element. Can you tell us more about the stoichiometric ratio of your elements?
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