Dear Shivesh Yadav,

One possibility to determine the structure of your samples is to inspect them using high-resolution transmission electron microscopy. The best thing would be to increase the TEM magnification so that the image (in real space) is filled by the feature of interest (in your case the nanowires) as much as possible. Then you should check and analyze the electron diffraction pattern (in reciprocal space) corresponding to the image. Thus, you should be in the position to obtain a similar info in comparison with the analysis of a powder X-ray spectrum. You should watch for the background, though. Indeed, the electron beam of TEM could pass right through your wires, and this could mean you end up analysig the underlying support.

Hope it helps.

Best Regards

I am not an expert in diffraction methods, but if I remember well TEM can be used to observe local electorn diffraction patterns which provide some limited information on the crystal structure. See e.g.

http://en.wikipedia.org/wiki/Electron_diffraction

http://www.icdd.com/ppxrd/10/presentations/PPXRD-10_Stavros_Nikolopoulos.pdf

The latter seems to be especially related to your problem. I hope some experts of the field can help you more directly

Supporting the comment of Gyorgy Banhegyi , i think that SADP can be used to find the lattice structure and constants from that diffraction pattern.

Dear Shivesh Yadav,

One possibility to determine the structure of your samples is to inspect them using high-resolution transmission electron microscopy. The best thing would be to increase the TEM magnification so that the image (in real space) is filled by the feature of interest (in your case the nanowires) as much as possible. Then you should check and analyze the electron diffraction pattern (in reciprocal space) corresponding to the image. Thus, you should be in the position to obtain a similar info in comparison with the analysis of a powder X-ray spectrum. You should watch for the background, though. Indeed, the electron beam of TEM could pass right through your wires, and this could mean you end up analysig the underlying support.

Hope it helps.

Best Regards

I think you should use HAADF-STEM method for more accurate analysis.

SAED can be directly used to perform unit cell determination just like the paper "A Method for Structure Analysis of Nanomaterials by Electron Diffraction: Phase Identification and Unit Cell Determination".

Accuracry of lattice parameters from SAED is only about 2 percent based on the fact that the camera length is manually calibrated using ring pattern of the standard Au or Al specimen. You can mix a little amount of standard polycrystals with your undermeasured specimen, and the recorded pattern contains both your specimen's information and the standard diffraction signal which can be used to internal calibration your pattern based on the PDF card. Under this route accuracy could be better than the traditional external calibration.

@Volker Klemm：If fortunately you can get a ring pattern from the diffraction pattern, it is simply to refine unit cell similar with the traditional X-ray diffraction analysis. If you specimen is with high crystallinity, spot-like pattern you can get after tilt and rotate specimen to the zone axis. But it commonly can't work for your specimen with small crystal size and poor morphology. Random electron diffraction pattern you can use to determine unit cell similar to our previous work "A Method for Structure Analysis of Nanomaterials by Electron Diffraction: Phase Identification and Unit Cell Determination"

Dear all, this I think that XRD might be used: Disperse you sample on a smooth carrier substrate and illuminate your sample in grazing incidence. This way you will suppress the bulk contributions and only measure the surface, as the X-rays will not penetrate into your substrate for incidence angles close to the critical anlge of total reflection. Then you may measure the XRD in an asymmetric geometry, i.e. the usually measured 2-Theta with respect to the small (and fixed!!!) incidence angle. The intensities will be smaller, but the signal only come from the region where your nanomaterial is present.

A second opportunity will be the measurment of the X-ray absorption fine structure (EXAFS or XANES) in fluorescence mode, which also may give you the desired information!

Best regards, Dirk

Dear S. Y

you can try High resolution TEM to obtain the lattice parameters either from image by measuring distance of lattice fingerprints or from the electron diffraction pattern of the selected area within image, that's help surely

Regards,

Ahmed

High resolution TEM and selective area electron diffraction. CBED will give accuracy but hard to do

Have you tried SAXS or GI-SAXS? Check the SAED under HR-TEM might give you diffraction patterns