The solid state interaction of the Zn1−xCoxO nominal system was investigated by

means of diffusion couples and analysis of co-precipitated samples. The formation

of a homogeneous Co:ZnO solid solution was found to be determined by the

crystal structure from which CoII ions diffuse into the wurtzite lattice. No diffusion

was observed whenever the CoO rock-salt structure was formed from the CoII

precursor. On the contrary, the diffusion from the Co3O4 spinel phase was feasible

but has a limited temperature range defined by the reduction at a high temperature

of CoIII–CoII, since this process again led to the formation of the rock-salt structure.

However, when using a highly reactive and homogeneous co-precipitated starting

powder, neither the spinel phase nor the rock-salt structure was formed, and a

CoII:ZnO solid solution was obtained, which remained stable up to high

temperatures.

Influence of Crystal Structure on the Coii Diffusion Behaviour in the Zn1−xCoxO

System. M.Peiteado, D.Makovec, M.Villegas, A.C.Caballero: Journal of Solid State

Chemistry, 2008, 181[9], 2456-61