Surface Chemical Studies of Manganese Dioxides

The stoichiometric form has the rutile structure and is easily obtained by heating Mn(II) nitrate (Sec. 12.2.3(a). It is characterised as described in Sec.2.1 and analysed by 

Heat Mn(N03)2 in a porcelain dish until no more NO2 fumes are produced. Grind the product well, reheat in a muffle furnace at 673 K to constant weight. Using standard sieves, separate the fraction -0.037+0.010 mm. Characterise the powder with the available instrumental techniques. For X-ray difffation, regrind to a very fine powder and keep in a desiccator prior to analysis. For thermogravimetric or differential thermal analysis (Sec.2.6.1 2.6.3) use a rate of heating of 5 or 10 C per minute. 

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