Collect. Czech. Chem. Commun. 1995, 60, 969-976

Lithium and Ammonium Selenates

David Havlíček, Zdeněk Mička and Radka Boublíková

Department of Inorganic Chemistry, Charles University, 128 40 Prague 2, Czech Republic


The Li2SeO4-H2SeO4-H2O and (NH4)2SeO4-Li2SeO4-H2O systems were studied at 30 °C to obtain data for determining the conditions of formation of the compound (NH4)4LiH3(SeO4)4, whose characteristics correspond to those of substances possessing significant dielectric properties. The results were used to construct the pseudoternary LiNH4SeO4-NH4HSeO4 -H2O section in the quaternary system, which gave evidence that only (NH4)3H(SeO4)2 forms in the crystallization region of the compound sought. Attention was also paid to lithium ammonium selenate, which was characterized by its X-ray, spectral, and thermal analysis data.