**5. Conclusions**

The interest of using microwaves in obtaining oxide nanostructures by reactions in solutions is rather high, leading to obtaining powders or films with enhanced properties.

According to the literature data, the MW irradiation in the sol–gel synthesis was used, most frequently, for precipitation of nanocrystalline metal oxides, for thermal treatment to crystallize the amorphous oxide nanopowders as well as for drying and thermally treatment of the oxide films.

However, the influence of the microwaves on the chemical reactions that take place during the sol–gel synthesis is less investigated.

Results regarding the formation of pure or doped nanostructures, as well as oxide compound, by sol–gel method in the presence or absence of microwave are presented.

The main results of the studies have shown that in all cases in the presence of microwave formation different molecular species is observed with a positive influence on the properties of the resulted nanostructure.

The advantage of using the MW-assited sol–gel method is a more shorter time of synthesis and obtaining nanostructures with improved properties.

The obtained results are of interest, but could be considered preliminary and systematic studies on the chemical processes induced by the microwaves should be continued.
