TEM images and electron diffraction patterns for amorphous and crystalline GeTe nanoparticles. (a),(b) Low-resolution TEM images for amorphous (a) and crystalline (b) GeTe nanoparticles. (c),(d) Typical high-resolution TEM images of amorphous (c) and crystalline (d) GeTe nanoparticles. The approximate area of the amorphous particle in (c) is marked for clarity. (e),(f) Selected-area electron diffraction patterns for amorphous (e) and crystalline (f) GeTe nanoparticles.