I am working on green synthesized Palladium NPs, I have done 2 times XRD of dried Pd Nps, i am getting the spectra of Pd NPs which is attached below, in which only (200) peak is visible, other peaks are not visible. how we can give the better explanation of this spectra. please suggest some useful literature also.
Basically, its is not spectra but diffractogram. How you have prepared your XRD sample? Preferred orientation might cause unexpected intensities of the diffraction peaks making the other smaller and the other higher. The two big peaks clearly visible in the diffractogram are relatively sharp so the crystallite size seems not to be so small. One explanation is that there are few larger crystalline particles in the sample while the other part of the sample is disordered.
I'm wondering why you ignore the peak around 30. And there are some small peaks. Without taking account them, you can't analyze this data. Perhaps, there is something that is not Pd... PdO?
You may try washing your sample with distilled water and grinding it into a very fine powder. That may help you get better XRD peaks. If that does not work you can try annealing.
How big are your nano particles? Essentially the XRD measures the "length" of order in a material. You know that as the particles become less ordered that the peaks broaden and therefore get smaller but this can happen due to size effects too. In fact, a better technique to characterise your particles is by TEM and selected area diffraction or by imaging the lattice fringes.
Basically, its is not spectra but diffractogram. How you have prepared your XRD sample? Preferred orientation might cause unexpected intensities of the diffraction peaks making the other smaller and the other higher. The two big peaks clearly visible in the diffractogram are relatively sharp so the crystallite size seems not to be so small. One explanation is that there are few larger crystalline particles in the sample while the other part of the sample is disordered.
What size do you expect your nanoparticle to be? as Lehto pointed out from the spectra, the powders don't seem nano because peaks are too sharps. You can easily estimate roughly crystallite size from FWHM. Peaks may indeed be produced by some big particles with preferential orientation. Also double check that during sample preparation you didn't contaminate the material.
thank-you all your information is qualitatively useful for me. Thanks Macro, Vesa-Pekka and Yoshiki Fukada.
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