Sol gel synthesis of zinc oxide films doped with transition metals

Zinc oxide is a wide band gap semiconductor that finds application in varistors and piezoelectric devrces .. Recent research has focussed on dissolving enough magnetic transition metal (TM) ions in the wurzite to make a ferromagnetic semiconductor. Thin films of ZnO have been prepared using a sol gel route. Zinc acetate was dissolved in ethylhexanoic acid and heated to obtain zinc ethylhexaoate. The solution was deposited on polycrystalline alumina substrates by "spin coating " successive layers. Transition metals could be dissolved readily in the zinc ethylhexanoate solutions as acetylacetonates hence ZnO films containing Co. A series of solutions were prepared to determine the solubility limit of the transition metal in the wurzite structure. The phase formation was studied using X ray diffractometry to determine the optimum crystallisation temperature and observe any second phases. formed by the addition excess transition metal.