It is known that platinum is crystallized in the face centered cubic (fcc) structure with 3 peaks in the range of 2θ=5-80o. I have platinized samples but XRD patterns show only Pt(111) and Pt(220). Indeed,no Pt(200) diffraction peak at 46.4° is present in these sample.What is the reason?
Your film likely has a strong orientation texture, which will result in peak intensities very different from a randomly oriented polycrystalline sample.
What is your platinized film thickness? If it is thin (>500-1000mircons) Bragg-Brentano XRD might not be suitable for your film. X-ray will penetrate through the film and reach the substrate resulting in substrate peaks. Grazing incidence XRD on the other hand will be effective for the surface planes. In that case you can miss some planes aswell. You need to set the angle carefully.
Your film likely has a strong orientation texture, which will result in peak intensities very different from a randomly oriented polycrystalline sample.
Dear colleague Mary Zare,
Have a nice time and good day,
Peace be up on you.
The structural properties of the material are function of preparation method, thermal literature, substrate type (in case on thin film)....etc. the all preferred orientations are not present always in all cases, so you need to process DTA or DSC to obtain the four distinct temperatures; the glass transition, Tg, the onset of crystallization, Tc, Peak of crystallization, Tp and melting point Tm. You can anneal your obtained material at the suitable annealing temperature according to the obtained values of Tc and Tm and also process XRD to the annealed material to check the preferred orientations.
The attach file may help you.
I wish this is useful and help you.
Yours
A. EL-Denglawey
Many thanks to the two down-voters of my answer,
Would you mind if both of you tell us the right answer? or what is the wrong of the produced answer? other wise your down-voting is fake.
I wish from RESEARCH GATE team to put conditions and reasons to down-vote of any answer.
Yours
A. El-Denglawey
The original question asked why only two peaks of platinum were resolved and the third was absent in a platinized sample.
A.B. Khiabani's answer, that Mary Zare's film was so thin that grazing incidence might be a better solution, is a possibility, but most likely does not apply here, as the absent peak is located at a 2theta angle between the other two - it would be more plausible if it were only the highest angle peak that was absent.
The fact that Mary Zare already sees two diffraction peaks means that she has made a crystalline film, and A Eldenglawey's answer that DSC and TGA would be useful to determine Tg, Tc, Tp, and Tm, is certainly true, but having such information would not answer the original question about the missing diffraction peak. Texture provides this answer.
FCC metals often show the 111 peak strongly enhanced (and the 200 strongly suppressed) in the direction normal to the surface because of the growth kinetics of the material.
Best regards, and thanks for a useful discussion.
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