Ti ions were incorporated as dopants into alumina crystals. Then, alumina peaks shifted a little to the lower angles. On the other hand, there is a sharp decrease in the intensity of alumina peaks. Regarding the mean atomic scattering factor, it is expected substitution of Al ions with Ti ones increases the intensity of alumina peaks. But as mentioned, there is a sharp decrease in the intensity of alumina peaks. Also, it seems that the width of the peaks in Ti-doped alumina is the same as alumina. Then what might be the reason for the intensity decrease by Ti ions?
Mehri Hashemzadeh I would like to say to get a proper idea about dopant behaviour, XRD is not sufficient but you may compare crystalline size using XRD. Also, I would be recommended you to do Raman (check Raman shift), XPS (confirm the formation of new bonds with Ti and Alumina using high-resolution spectra of Ti, O, and Al) and also DRS (check indirect band alignment of your composite with respect to the pure material). Try to make a conclusion based on these characterization techniques and also perform an XRF analysis to understand the composition of your material.
Your question lacks some information. We need to know about how you have doped Ti ions into alumina because it can affect the peak intensity and width.
Dear Mehri Hashemzadeh ,
in addiiton to what has been said by Leshan Usgodaarachchi and Hamid Ashrafi please bear in mind, that the x-ray mass-attenuation coeffcient of Ti is 4 times compared to that of Al at 8keV. Increase in x-ray attenuation will lead to decrease in XRD signal. So it is essential to know how much Ti is in your sample (compared to Al).
Little XRD peak shift means increase of interplanar spacing d; partly Al replacement by Ti will cause slight increase in lattice constant due to larger Ti diameter compared to Al, and thus slight larger d. So peak shift direction is ok.
With respect to peak width, I would expect slight peak broadening (and thus a peak decrease) due to the distortion of the alumina lattice by Ti, which is larger than Al.
Comparing XRD pattern from different samples with respect to their 'absolute' intensity is always crucial because you to have to very properly set up your experiment for such a comparison.
You should share your sample pattern...
By the way;
do you have powdered sample or film? In the case of film the XRD pattern will propably suffer from artifacts due to preferred orientation/texture in the film sample.
So far my comments;
best regards
G.M.
Leshan Usgodaarachchi Gerhard Martens Hamid Ashrafi
Many thanks for your attention.
I characterized my samples by different techniques especially EDS and Raman spectroscopy. Regarding Raman spectra, I am sure that Ti was doped into alumina. But it is interesting for me that doping Ti into alumina decreased the intensity of XRD peaks of alumina. Now I would like to know how may dopant affect the intensity of XRD peaks?
Please find the XRD graphs in the attachment.
Mehri Hashemzadeh can you share Raman and XPS analysis spectrums. Did u observe any peak positions shift over here?
Leshan Usgodaarachchi
I did not do XPS analysis on the samples. but the Raman spectroscopy results were similar to the graphs attached here.
Mehri Hashemzadeh the minimum detection limit (5 to 50 μg) of Raman spectroscopy is well enough to understand the doping effect if your material is doped properly. What are your green and blue line?
However, due to the absence of peaks related to the Ti it is very hard to make any suggestions. The best what you have to do is perform XRF in different spots and examine whether Ti is present in your sample.
What is your synthesis methodology?
This attachment would be a reference to you for understanding the doping effect
Dear Leshan Usgodaarachchi
Thank you very much for your attention;
Then I should do some other complementary tests.
- Badges
- Science topic
- Similar topics
- Phytochemistry
- Extracts