Wachstumsformen von tetragonalen Erdalkaliwolframaten in Schmelzlösungen und deren Deutung

Investigations on solubility of CaWO₄ in NaCl melts (ANIKIN ) were extended to BaWO₄ and SrWO₄. – Crystals of tungstates of Ca, Ba, and Sr from NaCl and KCl fluxes respectively were grown at temperatures from 950 to 650°C at cooling rates from 2 to 50 grd. h⁻¹. Marked differences in the forms of these tungstates did not occur. Among many whiskers bipyramidal crystals grew with dendritic, sceletal and hollow transitions forms. The theoretically calculated morphological succession (PBC model) is realised by the faces of the whiskers and platelets (110] and 100] zones). The remaining crystals – due to face specific adsorption – show other forms similar to those in nature. – Verneuil grown crystals, however, developed – free, from adsorption phenomena – {110} and {001} forms respectively.