Hi...Mohamed, In fact you can find in various journals'  articles concerning Gold (Bulk and Nanoparticles). The size , of course is so different. You can see from SEM/TEM data Au-spherical nanoparticles and also from UV-Vis spectroscopy (a shift - red). 

Regarding crystal structure for bulk and NP's Au, it is clear stated that the nanoparticles possess a well-defined atomic arrangement resembling the face-centered cubic (fcc) structure occurring with bulk gold. The fcc-type features of this arrangement become more prominent with increasing nano-particle size (see ref : Valeri Petkov, Yong Peng, Geoff Williams, Baohua Huang, Donald Tomalia, and Yang Ren

Phys. Rev. B 72, 195402 – Published 3 November 2005).  In my opinion, the difference which is appeared is the FWHM (representative peaks of XRD pattern) of both bulk and NPs' Au.  Hope this will be useful.

Rudy Situmeang

Hi...Mohamed, In fact you can find in various journals'  articles concerning Gold (Bulk and Nanoparticles). The size , of course is so different. You can see from SEM/TEM data Au-spherical nanoparticles and also from UV-Vis spectroscopy (a shift - red). 

Regarding crystal structure for bulk and NP's Au, it is clear stated that the nanoparticles possess a well-defined atomic arrangement resembling the face-centered cubic (fcc) structure occurring with bulk gold. The fcc-type features of this arrangement become more prominent with increasing nano-particle size (see ref : Valeri Petkov, Yong Peng, Geoff Williams, Baohua Huang, Donald Tomalia, and Yang Ren

Phys. Rev. B 72, 195402 – Published 3 November 2005).  In my opinion, the difference which is appeared is the FWHM (representative peaks of XRD pattern) of both bulk and NPs' Au.  Hope this will be useful.

Rudy Situmeang

It is surely exists a difference between them, the peaks of XRD for bulk gold is more intensity and sharp than gold  nanoparticles and obtain shifting in angles in some planes of the structure. 

Hello Mohamed,

I agree with Rudy, and to complete the answer the difference on the XRD that you will see is the broad of the peak. Nanoparticles cause the diffraction peaks to be broad, and also you can estimate the crystallite size using the Scherrer Equation.

About the position of EDS, it should never change. This is the energy of excitation of a particular metal, if the pattern shifts you should consider calibrate your equipment.

Best regards.

Dear Dr. Morsi:

As a whole, the term bulk is not defined at nanoparticle.  This find is assigned to a small number of atoms inner to the nanoparticle, as a matter of fact major fraction of number  of atom of a nanoparticle are positioned at surface.  In this sense, an authentic nanoparticles is an increadible manner of transport surface.

From submicrometric scale, the concept of bulk emerge in a gradual way. In this sense, for bulk properties observed via X ray diffraction are expected the existance of defect and a low level of stress/strain when a comparision is carried out.

Furthermore, method of preparation can exert some influence at about characteristics observed via difractogram, in specific  difraction lines (low intensity, 2-theta shiftting). 

The EDX "position" exibit a more sensible approach since another factors can be involved.

Kind regards

Marcos Nobre

Gold in bulk sample , it is face centered cubic structure  in the nano particle , analogous to the fourteen Bravais latices of the triperiodic crystal there are five diperiodic nets . the area unit of a diperiodic net analogous to the triperiodic unit cell is called the unit mesh in terms of ther unit mesh vectors..The XRD peaks of nanoparticles are broad.