Peculiarities of doping of ZnO:Mn nanocrystals during their synthesis by the aerosol pyrolysis method
Samples of ZnO:Mn nanocrystals with Mn concentrations of 2 and 4 at.% were synthesized by ultrasonic aerosol pyrolysis. The synthesis was carried out at 550°C using aqueous solutions of zinc and manganese nitrates. The samples obtained were subjected to heat treatment at 550°C and 850°C in air for 1 hour. The study of the samples by XRD and EPR methods shows that during the synthesis the process of doping ZnO nanocrystals with manganese occurs only partially, on the surface, in the near-surface layer. Residues of the Mn impurity are located on the surface of nanocrystals and appear during annealing at 550°С in the form of manganese oxides (Mn2O3). During heat treatment at 850°C, decomposition of Mn2O3 and bulk doping of ZnO:Mn nanocrystals occur.