GOSPODINOV, STANCHEVA: SELENITES AND HYDROGEN SELENITES OF SAMARIUM 1063
another mole of SeO2 and a basic salt with composition Sm2O2×SeO3 is formed. Com-
plete decomposition to Sm2O3 takes place at a temperature higher than 1000°C. The
mass loss at 1050°C is 59.57 vs. 60.48 mass% calculated theoretically.
The decomposition stages for both salts were confirmed by identifying the inter-
mediate decomposition products obtained and also by chemical and X-ray phase
analysis of these products.
The lattice parameters of the unit cells of the selenites obtained from the three-
component system and those obtained by their thermal decomposition were determined
(Table 2) with an exception of Sm2(SeO3)3·4H2O. Our calculation for the parameters of
the unit cells of SmH(SeO3)2·2H2O are in good agreement with those reported in [8].
This paper represents continuation of our investigation on the three-component
systems of the type Ln2O3–SeO2–H2O [14–22].
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