I see no diffraction contrast of crystalline material only scattering absorption contrast of elongated heap. If you love the term nanoparticles so, then try with darkfield prove that.

Quiet resemblance to nanorods

Dear Dr. Klemm

Thank you. I really don't underestand what you mean by " only scattering absorption contrast of elongated heap" can you explain a bit more?

Dear Mr. Shafqat and Mr. Son The Le

Thanks for your answer. But aren't they much bigger than the normal size of "nanorods"?

I agree with "Son The Le", I think SEM analysis can be very useful to undrestand the morphology of your sample.

Hi Ramin, here are some sheets of my lecture regarding amorphous scatterer and scattering absorption contrast in TEM:

I also think Nanorod. You can do SEM and AFM....

 A scanning electron microscope (SEM) scans a focused electron beam over a surface to create an image that can be used to obtain information about the surface topography and composition. You need to do SEM.

Thank you all for your time and answers. So the conclusion of the talks is that these particles are rod-like, but for a better understanding of their morphology, SEM scans needed.

But as a final question, Are these particles "nanoparticles" or not (due to their size)? 

According to the ISO standard for Nanotechnology a nanoparticle is defined as a particle with all its external dimensions less than 100 nm, which means your particles does not qualify for this.

They are however nano-structured if they have at least one dimension  below 100 nm. If the length to widht ratio also is above 3, they qualify as nano-fibers (or nano-rods if rigid).

Dear Dr.Levin

Thank you. That was exactly why I was confused.

Dear Dr.Nobre

Thank you so much for you complete answer. So as a conclusion due to it's size and shape, shall I call it "3D-nanoparticle" or "2D-nanofiber"?

Thank you all for your participation in this discussion, sharing your information and ideas with me and helping me to find the best answer.