In particular, a superlattice can be seen as an ordered structure with alternating objects of similar size and different composition, e.g. elements of high and low density (W/C, Mo/C, Ni/C), semiconductors (AlAs / GaAs), ferromagnetic and nonmagnetic metals (Co-Ni-Cu/Cu), or ferromagnetic F and superconductor S (F/S, where F = Fe, Co, Gd, Ni, and S = Nb, Pb, V), or ordered structure of monodisperse nanoparticles, e.g quantum dots. Due to the fact that objects' size is comparable to the de Broglie electron wavelength, superlattices show the effects of size quantisation of electronic properties.