Dear M. BENDOUMIA 

Please re-attach the images because they can't open

I have re-attached

thank's sir

If you know the crystal structure, you can index spots in the FFT. Of course, if your structure is simple, you can determine the lattice parameters. But from a single HRTEM image to derive the crystal structure seems hard. 

Dear M. BENDOUMIA,

I don´t think that determination of crystal lattice and lattice parameter as well is possible from your FFT image. The FFT pattern is conversion of real space to frequency space. If you create FFT from captured image the source of frequencies are dots (imaged atoms probably). So you have to have perfect HRTEM image. I can see the astigmatism on you FFT pattern, so if you want to read out the interplanar distancies take into account this deviation. For extracting of analytical data from HRTEM images you need many defocal series from the same place and tilt the specimen to another HRTEM position and gather the data again.

Thanks for your helpful answers

Can I get some suggestion of bibliography that can help me to do the right experiments for extracting analytical data?

Best regards

Dear BENDOUMIA,

I do not know the second image, but the first image corresponds to the selected-area diffraction electron technic (SAED) and show a cubic structure of particle. The directions of plans are not indicated.

See: Monoclinic to cubic phase transformation od ZrO2 induced by ball milling.

XIANGFA LIU.

Sir Sari

The first image is not a SAED it is a FFT (fast Fourier transform) I have obtained from my HRTEM result using digital micrograph software.

And sir how can you be sure that is a cubic and not an other structure ?

best regards

the image is the same for both technics. About the structure, I leave you the care to find the answer in this article.

Best regards.

@ M. BENDOUMIA, Please attach your HRTEM image. To know the crystal structure and lattice parameter, first you need to identify what your material and the possible crystal. To know these, you can investigate your material using XRD. Secondly, you may need several diffraction patterns (FFT images) in order to get enough data for lattice parameter.calculation.