To obtain materials with very special properties, it may be necessary to reduce the interaction between the particles by keeping them
in a certain distance.
This distance may be smaller, in the case of tunnelling exchange and is larger in the case of dipole –
dipole interaction. This leads to the concept of nanocomposites consisting of two phases: An active one and a passive distance
The optimal distribution of these phases is obtained by coating the active particles with a second phase.
Additionally, by appropriate selecting of the materials for the core and the coating, nanocomposites allow combining different
properties in one particle.
For further information please visit our Intensive Course Nanomaterials.
Electron micrograph of nanocomposite particles consisting of a ZrO2 core and an Al2O3
coating. The points visible in the central particle represent the Zr ions in the crystal lattice of the zirconia. The alumina coating
is not crystallized.
Micrograph taken from the paper:
D. Vollath, D. V. Szabó, in: Innovative Processing of Films and Nanocrystalline Powders, Imperial Press, London (2002) p. 219