From a crystallography perspective, according to the “oriented attachment mechanism”, which was first explored by Penn and Banfield [31], adjacent particles share a common crystallographic orientation, followed by joining of these particles at a planar interface. Bonding between adjacent nanoparticles reduces the overall energy by removing the surface energy associated with unsatisfied bonds. Clearly, this attachment mechanism is reflected by the results in Fig. 6. The ZrB2 nanoparticles connected with each other via the “oriented attachment mechanism” and a reduction in surface free energy was achieved by the complete removal of pairs of surfaces. Imperfect oriented attachment of nanocrystals can generate dislocations. Any defects observed by HRTEM can be attributed to the growth process.