Figure 2
From: Enhanced Thermal Conductivity and Viscosity of Nanodiamond-Nickel Nanocomposite Nanofluids

Structure of c-ND and Ni nanoparticles.
(a) Bright-field TEM image of c-ND particles. (b) High-resolution TEM image of single nanodiamond particle and electron diffraction pattern (upper inset of Figure 2b) shows crystalline nature of the diamond nanoparticles. (c) High-resolution TEM image of crystalline Ni nanoparticles and corresponding electron diffraction pattern (lower inset of Figure 2c).