Synthesis of Delafossite-Type Ag0.9MnO2 by the Precipitation Method at Room Temperature

A delafossite-type Ag-Mn oxide was successfully synthesized using the precipitation method at room temperature. The delafossite is Ag + -deficient and has a chemical composition of Ag 0.9 MnO 2 . Thermogravimetry of the Ag 0.9 MnO 2 delafossite revealed that on heating to 900 °C, it decomposed to Ag and Mn 2 O 3 in air and to Ag and Mn 3 O 4 under N 2 . While cooling to room temperature in air, the delafossite phase reformed from Ag and Mn 3 O 4 . The reversibility of the decomposition/reformation process is related to the similarity between the delafossite and spinel-type structures, both of which contain an octahedral layer. The reformation process could be used as a new synthetic route to Ag + -containing delafossite-type oxides.