Most developed precipitation methods for synthesizing

The doping by SO42−-ions can be realized in several different ways when ammonium sulfate is used as SO42−-ion sources. The ammonium sulfate can be added into reaction mixture 'Wortmannin' during precipitation [19], [27] and [30] during aging [7] and [17], or the resulting precipitant can be rinsed by ammonium sulfate solution [16]. Alternatively, SO42−-containing substances can be used as a starting material in the reaction [5], [25], [28] and [29].