Alkali Rare Earth Selenates

Ammonium double selenates of the type NH4M(Se04)2 nH20 and (NH4)3M(Se04)3 (only known with M = Sc) are usually obtained from aqueous solutions. Unlike the other alkali rare earth selenates, the anhydrous selenates NH4M(Se04)2 could not be obtained by heating the hydrates, except for M = Sm, Ho. 

The volume Rare Earth Elements C 9 deals with the rare earth selenides, oxide selenides, selenites, and selenates, as well as the associated alkali double compounds, diselenate nitrates, and the selenide halides. So far as meaningful and as in all earlier volumes of Rare Earth Elements Series C ( Seltenerdelemente Reihe C), comparative data are presented in sections preceding treatment of the individual compounds and systems. 

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