There is  a big difference between Amorphous shell and Crystalline core in core/shell nanoparticles. My opinion you can see and knows this differance if you examine your material under the TEM  and see the diffraction pattern also at this time you will see the differences between them. 

Unlike crystalline core, amorphous shell doesn't have ordered structure.

Dear Anastasia Kholodkova & Hamida Mohammed Bakr Darwish

Excuse me, My question was incorrected, my question is this:

What is the difference between Amorphous shell and Crystalline Shell in core/shell nanoparticles?which is better why?