How to avoid formation of Mn2+ in strongly acidic conditions during formation of phases like K2SiF6:Mn4+?

I'm trying to synthesize phases M2EF6:Mn4+ (M - Na, K, E - Si, Ti, Ge etc.) in nanostate using hydrothermal process. As a source of manganese I used KMnO4. Other materials in the typical synthesis...

10 October 2017 1,288 8 View